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RFC 2566

 
 
 

Internet Printing Protocol/1.0: Model and Semantics

Part 2 of 7, p. 22 to 50
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3.1.4 Character Set and Natural Language Operation Attributes

   Some Job and Printer attributes have values that are text strings and
   names intended for human understanding rather than machine
   understanding (see the 'text' and 'name' attribute syntax
   descriptions in section 4.1).  The following sections describe two
   special Operation Attributes called "attributes-charset" and
   "attributes-natural-language".  These attributes are always part of
   the Operation Attributes group.  For most attribute groups, the order
   of the attributes within the group is not important.  However, for
   these two attributes within the Operation Attributes group, the order
   is critical.  The "attributes-charset" attribute MUST be the first
   attribute in the group and the "attributes-natural-language"
   attribute MUST be the second attribute in the group.  In other words,
   these attributes MUST be supplied in every IPP request and response,
   they MUST come first in the group, and MUST come in the specified
   order.  For job creation operations, the IPP Printer implementation
   saves these two attributes with the new Job object as Job Description
   attributes.  For the sake of brevity in this document, these
   operation attribute descriptions are not repeated with every
   operation request and response, but have a reference back to this
   section instead.

3.1.4.1 Request Operation Attributes

   The client MUST supply and the Printer object MUST support the
   following REQUIRED operation attributes in every IPP/1.0 operation
   request:

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     "attributes-charset" (charset):
        This operation attribute identifies the charset (coded character
        set and encoding method) used by any 'text' and 'name'
        attributes that the client is supplying in this request.  It
        also identifies the charset that the Printer object MUST use (if
        supported) for all 'text' and 'name' attributes and status
        messages that the Printer object returns in the response to this
        request. See Sections 4.1.1 and 4.1.2 for the specification of
        the 'text' and 'name' attribute syntaxes.

        All clients and IPP objects MUST support the 'utf-8' charset
        [RFC2279] and MAY support additional charsets provided that they
        are registered with IANA [IANA-CS].  If the Printer object does
        not support the client supplied charset value, the Printer
        object MUST reject the request, set the "attributes-charset" to
        'utf-8' in the response, and return the 'client-error-charset-
        not-supported' status code and any 'text' or 'name' attributes
        using the 'utf-8' charset.  The Printer object MUST indicate the
        charset(s) supported as the values of the "charset-supported"
        Printer attribute (see Section 4.4.15), so that the client can
        query to determine which charset(s) are supported.

        Note to client implementers: Since IPP objects are only required
        to support the 'utf-8' charset, in order to maximize
        interoperability with multiple IPP object implementations, a
        client may want to supply 'utf-8' in the "attributes-charset"
        operation attribute, even though the client is only passing and
        able to present a simpler charset, such as US-ASCII or ISO-
        8859-1.  Then the client will have to filter out (or charset
        convert) those characters that are returned in the response that
        it cannot present to its user.  On the other hand, if both the
        client and the IPP objects also support a charset in common
        besides utf-8, the client may want to use that charset in order
        to avoid charset conversion or data loss.

        See the 'charset' attribute syntax description in Section 4.1.7
        for the syntax and semantic interpretation of the values of this
        attribute and for example values.

     "attributes-natural-language" (naturalLanguage):
        This operation attribute identifies the natural language used by
        any 'text' and 'name' attributes that the client is supplying in
        this request.  This attribute also identifies the natural
        language that the Printer object SHOULD use for all 'text' and '
        name' attributes and status messages that the Printer object
        returns in the response to this request.

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        There are no REQUIRED natural languages required for the Printer
        object to support.  However, the Printer object's "generated-
        natural-language-supported" attribute identifies the natural
        languages supported by the Printer object and any contained Job
        objects for all text strings generated by the IPP object.  A
        client MAY query this attribute to determine which natural
        language(s) are supported for generated messages.

        For any of the attributes for which the Printer object generates
        text, i.e., for the "job-state-message", "printer-state-
        message", and status messages (see Section 3.1.6), the Printer
        object MUST be able to generate these text strings in any of its
        supported natural languages.  If the client requests a natural
        language that is not supported, the Printer object MUST return
        these generated messages in the Printer's configured natural
        language as specified by the Printer's "natural-language-
        configured" attribute" (see Section 4.4.16).

        For other 'text' and 'name' attributes supplied by the client,
        authentication system, operator, system administrator, or
        manufacturer (i.e., for "job-originating-user-name", "printer-
        name" (name), "printer-location" (text), "printer-info" (text),
        and "printer-make-and-model" (text)), the Printer object is only
        required to support the configured natural language of the
        Printer identified by the Printer object's "natural-language-
        configured" attribute, though support of additional natural
        languages for these attributes is permitted.

        For any 'text' or 'name' attribute in the request that is in a
        different natural language than the value supplied in the
        "attributes-natural-language" operation attribute, the client
        MUST use the Natural Language Override mechanism (see sections
        4.1.1.2 and 4.1.2.2) for each such attribute value supplied.
        The client MAY use the Natural Language Override mechanism
        redundantly, i.e., use it even when the value is in the same
        natural language as the value supplied in the "attributes-
        natural-language" operation attribute of the request.

        The IPP object MUST accept any natural language and any Natural
        Language Override, whether the IPP object supports that natural
        language or not (and independent of the value of the "ipp-
        attribute-fidelity" Operation attribute).  That is the IPP
        object accepts all client supplied values no matter what the
        values are in the Printer object's "generated-natural-language-
        supported" attribute.  That attribute, "generated-natural-
        language-supported", only applies to generated messages,

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        not client supplied messages.  The IPP object MUST remember that
        natural language for all client-supplied attributes, and when
        returning those attributes in response to a query, the IPP
        object MUST indicate that natural language.

        Each value whose attribute syntax type is 'text' or 'name' (see
        sections 4.1.1 and 4.1.2) has an Associated Natural-Language.
        This document does not specify how this association is stored in
        a Printer or Job object.  When such a value is encoded in a
        request or response, the natural language is either implicit or
        explicit:

             - In the implicit case, the value contains only the
               text/name value, and the language is specified by the
               "attributes-natural-language" operation attribute in the
               request or response (see sections 4.1.1.1
               textWithoutLanguage and 4.1.2.1 nameWithoutLanguage).

             - In the explicit case (also known as the Natural-Language
               Override case), the value contains both the language and
               the text/name value (see sections 4.1.1.2
               textWithLanguage and 4.1.2.2 nameWithLanguage).

        For example, the "job-name" attribute MAY be supplied by the
        client in a create request.  The text value for this attribute
        will be in the natural language identified by the "attribute-
        natural-language" attribute, or if different, as identified by
        the Natural Language Override mechanism.  If supplied, the IPP
        object will use the value of the "job-name" attribute to
        populate the Job object's "job-name" attribute.  Whenever any
        client queries the Job object's "job-name" attribute, the IPP
        object returns the attribute as stored and uses the Natural
        Language Override mechanism to specify the natural language, if
        it is different from that reported in the "attributes-natural-
        language" operation attribute of the response.  The IPP object
        MAY use the Natural Language Override mechanism redundantly,
        i.e., use it even when the value is in the same natural language
        as the value supplied in the "attributes-natural-language"
        operation attribute of the response.

        An IPP object MUST NOT reject a request based on a supplied
        natural language in an "attributes-natural-language" Operation
        attribute or in any attribute that uses the Natural Language
        Override.

        See the 'naturalLanguage' attribute syntax description in
        section 4.1.8 for the syntax and semantic interpretation of the
        values of this attribute and for example values.

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   Clients SHOULD NOT supply 'text' or 'name' attributes that use an
   illegal combination of natural language and charset.  For example,
   suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and
   'iso-8859-7'.  Suppose also, that it supports natural languages 'en'
   (English), 'fr' (French), and 'el' (Greek).  Although the Printer
   object supports the charset 'iso-8859-1' and natural language 'el',
   it probably does not support the combination of Greek text strings
   using the 'iso-8859-1' charset.  The Printer object handles this
   apparent incompatibility differently depending on the context in
   which it occurs:

     - In a create request: If the client supplies a text or name
       attribute (for example, the "job-name" operation attribute) that
       uses an apparently incompatible combination, it is a client
       choice that does not affect the Printer object or its correct
       operation.  Therefore, the Printer object simply accepts the
       client supplied value, stores it with the Job object, and
       responds back with the same combination whenever the client (or
       any client) queries for that attribute.
     - In a query-type operation, like Get-Printer-Attributes: If the
       client requests an apparently incompatible combination, the
       Printer object responds (as described in section 3.1.4.2) using
       the Printer's configured natural language rather than the natural
       language requested by the client.

   In either case, the Printer object does not reject the request
   because of the apparent incompatibility.  The potential incompatible
   combination of charset and natural language can occur either at the
   global operation level or at the Natural Language Override
   attribute-by-attribute level.  In addition, since the response always
   includes explicit charset and natural language information, there is
   never any question or ambiguity in how the client interprets the
   response.

3.1.4.2 Response Operation Attributes

   The Printer object MUST supply and the client MUST support the
   following REQUIRED operation attributes in every IPP/1.0 operation
   response:

     "attributes-charset" (charset):
        This operation attribute identifies the charset used by any '
        text' and 'name' attributes that the Printer object is returning
        in this response.  The value in this response MUST be the same
        value as the "attributes-charset" operation attribute supplied
        by the client in the request.  If this is not possible

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        (i.e., the charset requested is not supported), the request
        would have been rejected.  See "attributes-charset" described in
        Section 3.1.4.1 above.

        If the Printer object supports more than just the 'utf-8'
        charset, the Printer object MUST be able to code convert between
        each of the charsets supported on a highest fidelity possible
        basis in order to return the 'text' and 'name' attributes in the
        charset requested by the client.  However, some information loss
        MAY occur during the charset conversion depending on the
        charsets involved.  For example, the Printer object may convert
        from a UTF-8 'a' to a US-ASCII 'a' (with no loss of
        information), from an ISO Latin 1 CAPITAL LETTER A WITH ACUTE
        ACCENT to US-ASCII 'A' (losing the accent), or from a UTF-8
        Japanese Kanji character to some ISO Latin 1 error character
        indication such as '?', decimal code equivalent, or to the
        absence of a character, depending on implementation.

        Note: Whether an implementation that supports more than one
        charset stores the data in the charset supplied by the client or
        code converts to one of the other supported charsets, depends on
        implementation.  The strategy should try to minimize loss of
        information during code conversion.  On each response, such an
        implementation converts from its internal charset to that
        requested.

     "attributes-natural-language" (naturalLanguage):
        This operation attribute identifies the natural language used by
        any 'text' and 'name' attributes that the IPP object is
        returning in this response.  Unlike the "attributes-charset"
        operation attribute, the IPP object NEED NOT return the same
        value as that supplied by the client in the request.  The IPP
        object MAY return the natural language of the Job object or the
        Printer's configured natural language as identified by the
        Printer object's "natural-language-configured" attribute, rather
        than the natural language supplied by the client.  For any '
        text' or 'name' attribute or status message in the response that
        is in a different natural language than the value returned in
        the "attributes-natural-language" operation attribute, the IPP
        object MUST use the Natural Language Override mechanism (see
        sections 4.1.1.2 and 4.1.2.2) on each attribute value returned.
        The IPP object MAY use the Natural Language Override mechanism
        redundantly, i.e., use it even when the value is in the same
        natural language as the value supplied in the "attributes-
        natural-language" operation attribute of the response.

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3.1.5 Operation Targets

   All IPP operations are directed at IPP objects.  For Printer
   operations, the operation is always directed at a Printer object
   using one of its URIs (i.e., one of the values in the Printer
   object's "printer-uri-supported" attribute).  Even if the Printer
   object supports more than one URI, the client supplies only one URI
   as the target of the operation.  The client identifies the target
   object by supplying the correct URI in the "printer-uri (uri)"
   operation attribute.

   For Job operations, the operation is directed at either:

     - The Job object itself using the Job object's URI.  In this case,
       the client identifies the target object by supplying the correct
       URI in the "job-uri (uri)" operation attribute.
     - The Printer object that created the Job object using both the
       Printer objects URI and the Job object's Job ID.  Since the
       Printer object that created the Job object generated the Job ID,
       it MUST be able to correctly associate the client supplied Job ID
       with the correct Job object.  The client supplies the Printer
       object's URI in the "printer-uri (uri)" operation attribute and
       the Job object's Job ID in the "job-id (integer(1:MAX))"
       operation attribute.

   If the operation is directed at the Job object directly using the Job
   object's URI, the client MUST NOT include the redundant "job-id"
   operation attribute.

   The operation target attributes are REQUIRED operation attributes
   that MUST be included in every operation request.  Like the charset
   and natural language attributes (see section 3.1.4), the operation
   target attributes are specially ordered operation attributes.  In all
   cases, the operation target attributes immediately follow the
   "attributes-charset" and "attributes-natural-language" attributes
   within the operation attribute group, however the specific ordering
   rules are:

     - In the case where there is only one operation target attribute
       (i.e., either only the "printer-uri" attribute or only the "job-
       uri" attribute), that attribute MUST be the third attribute in
       the operation attributes group.
     - In the case where Job operations use two operation target
       attributes (i.e., the "printer-uri" and "job-id" attributes), the
       "printer-uri" attribute MUST be the third attribute and the
       "job-id" attribute MUST be the fourth attribute.

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   In all cases, the target URIs contained within the body of IPP
   operation requests and responses must be in absolute format rather
   than relative format (a relative URL identifies a resource with the
   scope of the HTTP server, but does not include scheme, host or port).

   The following rules apply to the use of port numbers in URIs that
   identify IPP objects:

     1. If the URI scheme allows the port number to be explicitly
        included in the URI string, and a port number is specified
        within the URI, then that port number MUST be used by the client
        to contact the IPP object.

     2. If the URI scheme allows the port number to be explicitly
        included in the URI string, and a port number is not specified
        within the URI, then default port number implied by that URI
        scheme MUST be used by the client to contact the IPP object.

     3. If the URI scheme does not allow an explicit port number to be
        specified within the URI, then the default port number implied
        by that URI MUST be used by the client to contact the IPP
        object.

   Note: The IPP encoding and transport document [RFC2565] shows a
   mapping of IPP onto HTTP/1.1 and defines a new default port number
   for using IPP over HTTP/1.1.

3.1.6 Operation Status Codes and Messages

   Every operation response includes a REQUIRED "status-code" parameter
   and an OPTIONAL "status-message" operation attribute.  The "status-
   code" provides information on the processing of a request.  A
   "status-message" attribute provides a short textual description of
   the status of the operation.  The status code is intended for use by
   automata, and the status message is intended for the human end user.
   If a response does include a "status-message" attribute, an IPP
   client NEED NOT examine or display the message, however it SHOULD do
   so in some implementation specific manner.

   The "status-code" value is a numeric value that has semantic meaning.
   The "status-code" syntax is similar to a "type2 enum" (see section
   4.1 on "Attribute Syntaxes") except that values can range only from
   0x0000 to 0x7FFF.  Section 13 describes the status codes, assigns the
   numeric values, and suggests a corresponding status message for each
   status code.  The "status-message" attribute's syntax is "text(255)".
   A client implementation of IPP SHOULD convert status code values into
   any localized message that has semantic meaning to the end user.

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   If the Printer object supports the "status-message" operation
   attribute, the Printer object MUST be able to generate this message
   in any of the natural languages identified by the Printer object's
   "generated-natural-language-supported" attribute (see the
   "attributes-natural-language" operation attribute specified in
   section 3.1.4.1).  As described in section 3.1.4.1 for any returned '
   text' attribute, if there is a choice for generating this message,
   the Printer object uses the natural language indicated by the value
   of the "attributes-natural-language" in the client request if
   supported, otherwise the Printer object uses the value in the Printer
   object's own "natural-language-configured" attribute.  If the Printer
   object supports the "status-message" operation attribute, it SHOULD
   use the REQUIRED 'utf-8' charset to return a status message for the
   following error status codes (see section 13): 'client-error-bad-
   request', 'client-error-charset-not-supported', 'server-error-
   internal-error', 'server-error-operation-not-supported', and '
   server-error-version-not-supported'.  In this case, it MUST set the
   value of the "attributes-charset" operation attribute to 'utf-8' in
   the error response.

3.1.7 Versions

   Each operation request and response carries with it a "version-
   number" parameter.  Each value of the "version-number" is in the form
   "X.Y" where X is the major version number and Y is the minor version
   number.  By including a version number in the client request, it
   allows the client  to identify which version of IPP it is interested
   in using.  If the IPP object does not support that version, the
   object responds with a status code of 'server-error-version-not-
   supported' along with the closest version number that is supported
   (see section 13.1.5.4).

   There is no version negotiation per se.  However, if after receiving
   a 'server-error-version-not-supported' status code from an IPP
   object, there is nothing that prevents a client from trying again
   with a different version number. In order to conform to IPP/1.0, an
   implementation MUST support at least version '1.0'.

   There is only one notion of "version number" that covers both IPP
   Model and IPP Protocol changes. Thus the version number MUST change
   when introducing a new version of the Model and Semantics document
   [RFC2566] or a new version of the Encoding and Transport document
   [RFC2565].

   Changes to the major version number indicate structural or syntactic
   changes that make it impossible for older version of IPP clients and
   Printer objects to correctly parse and process the new or changed
   attributes, operations and responses.  If the major version number

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   changes, the minor version numbers is set to zero.  As an example,
   adding the "ipp-attribute-fidelity" attribute (if it had not been
   part of version '1.0'), would have required a change to the major
   version number.  Items that might affect the changing of the major
   version number include any changes to the Model and Semantics
   document [RFC2566] or the Encoding and Transport [RFC2565] itself,
   such as:

     - reordering of ordered attributes or attribute sets
     - changes to the syntax of existing attributes
     - changing Operation or Job Template attributes from OPTIONAL to
       REQUIRED and vice versa
     - adding REQUIRED (for an IPP object to support) operation
       attributes
     - adding REQUIRED (for an IPP object to support) operation
       attribute groups
     - adding values to existing operation attributes
     - adding REQUIRED operations

   Changes to the minor version number indicate the addition of new
   features, attributes and attribute values that may not be understood
   by all IPP objects, but which can be ignored if not understood.
   Items that might affect the changing of the minor version number
   include any changes to the model objects and attributes but not the
   encoding and transport rules [RFC2565] (except adding attribute
   syntaxes).  Examples of such changes are:

     - grouping all extensions not included in a previous version into
       a new version
     - adding new attribute values
     - adding new object attributes
     - adding OPTIONAL (for an IPP object to support) operation
       attributes (i.e., those attributes that an IPP object can ignore
       without confusing clients)
     - adding OPTIONAL (for an IPP object to support) operation
       attribute groups (i.e., those attributes that an IPP object can
       ignore without confusing clients)
     - adding new attribute syntaxes
     - adding OPTIONAL operations
     - changing Job Description attributes or Printer Description
       attributes from OPTIONAL to REQUIRED or vice versa.

   The encoding of the "operation-id", the "version-number", the
   "status-code", and the "request-id" MUST NOT change over any version
   number (either major or minor).  This rule guarantees that all future
   versions will be backwards compatible with all previous versions (at
   least for checking the "operation-id", the "version-number", and the
   "request-id").  In addition, any protocol elements (attributes, error

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   codes, tags, etc.) that are not carried forward from one version to
   the next are deprecated so that they can never be reused with new
   semantics.

   Implementations that support a certain major version NEED NOT support
   ALL previous versions.  As each new major version is defined (through
   the release of a new specification), that major version will specify
   which previous major versions MUST be supported in compliant
   implementations.

3.1.8 Job Creation Operations

   In order to "submit a print job" and create a new Job object, a
   client issues a create request.  A create request is any one of
   following three operation requests:

     - The Print-Job Request: A client that wants to submit a print job
       with only a single document uses the Print-Job operation.  The
       operation allows for the client to "push" the document data to
       the Printer object by including the document data in the request
       itself.

     - The Print-URI Request: A client that wants to submit a print job
       with only a single document (where the Printer object "pulls" the
       document data instead of the client "pushing" the data to the
       Printer object) uses the Print-URI operation.   In this case, the
       client includes in the request only a URI reference to the
       document data (not the document data itself).

     - The Create-Job Request: A client that wants to submit a print job
       with multiple documents uses the Create-Job operation.  This
       operation is followed by an arbitrary number of Send-Document
       and/or Send-URI operations (each creating another document for
       the newly create Job object).  The Send-Document operation
       includes the document data in the request (the client "pushes"
       the document data to the printer), and the Send-URI operation
       includes only a URI reference to the document data in the request
       (the Printer "pulls" the document data from the referenced
       location).  The last Send-Document or Send-URI request for a
       given Job object includes a "last-document" operation attribute
       set to 'true' indicating that this is the last request.

   Throughout this model specification, the term "create request" is
   used to refer to any of these three operation requests.

   A Create-Job operation followed by only one Send-Document operation
   is semantically equivalent to a Print-Job operation, however, for
   performance reasons, the client SHOULD use the Print-Job operation

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   for all single document jobs.  Also, Print-Job is a REQUIRED
   operation (all implementations MUST support it) whereas Create-Job is
   an OPTIONAL operation, hence some implementations might not support
   it.

   Job submission time is the point in time when a client issues a
   create request.  The initial state of every Job object is the '
   pending' or 'pending-held' state.  Later, the Printer object begins
   processing the print job.  At this point in time, the Job object's
   state moves to 'processing'.  This is known as job processing time.
   There are validation checks that must be done at job submission time
   and others that must be performed at job processing time.

   At job submission time and at the time a Validate-Job operation is
   received, the Printer MUST do the following:

     1. Process the client supplied attributes and either accept or
        reject the request
     2. Validate the syntax of and support for the scheme of any client
        supplied URI

   At job submission time the Printer object MUST validate whether or
   not the supplied attributes, attribute syntaxes, and values are
   supported by matching them with the Printer object's corresponding
   "xxx-supported" attributes.  See section 3.2.1.2 for details.  [ipp-
   iig] presents suggested steps for an IPP object to either accept or
   reject any request and additional steps for processing create
   requests.

   At job submission time the Printer object NEED NOT perform the
   validation checks reserved for job processing time such as:

     1. Validating the document data
     2. Validating the actual contents of any client supplied URI
        (resolve the reference and follow the link to the document data)

   At job submission time, these additional job processing time
   validation checks are essentially useless, since they require
   actually parsing and interpreting the document data, are not
   guaranteed to be 100% accurate, and MUST be done, yet again, at job
   processing time.  Also, in the case of a URI, checking for
   availability at job submission time does not guarantee availability
   at job processing time.   In addition, at job processing time, the
   Printer object might discover any of the following conditions that
   were not detectable at job submission time:

     - runtime errors in the document data,
     - nested document data that is in an unsupported format,

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     - the URI reference is no longer valid (i.e., the server hosting
       the document might be down), or
     - any other job processing error

   At job processing time, since the Printer object has already
   responded with a successful status code in the response to the create
   request, if the Printer object detects an error, the Printer object
   is unable to inform the end user of the error with an operation
   status code.   In this case, the Printer, depending on the error, can
   set the "job-state", "job-state-reasons", or "job-state-message"
   attributes to the appropriate value(s) so that later queries can
   report the correct job status.

   Note: Asynchronous notification of events is outside the scope of
   IPP/1.0.

3.2 Printer Operations

   All Printer operations are directed at Printer objects.  A client
   MUST always supply the "printer-uri" operation attribute in order to
   identify the correct target of the operation.

3.2.1 Print-Job Operation

   This REQUIRED operation allows a client to submit a print job with
   only one document and supply the document data (rather than just a
   reference to the data).  See Section 15 for the suggested steps for
   processing create operations and their Operation and Job Template
   attributes.

3.2.1.1 Print-Job Request

   The following groups of attributes are supplied as part of the
   Print-Job Request:

   Group 1: Operation Attributes

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.1.  The Printer object
        MUST copy these values to the corresponding Job Description
        attributes described in sections 4.3.23 and 4.3.24.

     Target:
        The "printer-uri" (uri) operation attribute which is the target
        for this operation as described in section 3.1.5.

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     Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.

     "job-name" (name(MAX)):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  It contains the client
        supplied Job name.  If this attribute is supplied by the client,
        its value is used for the "job-name" attribute of the newly
        created Job object.  The client MAY automatically include any
        information that will help the end-user distinguish amongst
        his/her jobs, such as the name of the application program along
        with information from the document, such as the document name,
        document subject, or source file name.  If this attribute is not
        supplied by the client, the Printer generates a name to use in
        the "job-name" attribute of the newly created Job object (see
        Section 4.3.5).

     "ipp-attribute-fidelity" (boolean):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  The value 'true' indicates
        that total fidelity to client supplied Job Template attributes
        and values is required, else the Printer object MUST reject the
        Print-Job request.  The value 'false' indicates that a
        reasonable attempt to print the Job object is acceptable and the
        Printer object MUST accept the Print-job request. If not
        supplied, the Printer object assumes the value is 'false'.  All
        Printer objects MUST support both types of job processing.  See
        section 15 for a full description of "ipp-attribute-fidelity"
        and its relationship to other attributes, especially the Printer
        object's "pdl-override-supported" attribute.

     "document-name" (name(MAX)):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.   It contains the client
        supplied document name.  The document name MAY be different than
        the Job name.  Typically, the client software automatically
        supplies the document name on behalf of the end user by using a
        file name or an application generated name.  If this attribute
        is supplied, its value can be used in a manner defined by each
        implementation.  Examples include: printed along with the Job
        (job start sheet, page adornments, etc.), used by accounting or
        resource tracking management tools, or even stored along with
        the document as a document level attribute.  IPP/1.0 does not
        support the concept of document level attributes.

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     "document-format" (mimeMediaType) :
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  The value of this attribute
        identifies the format of the supplied document data.  If the
        client does not supply this attribute, the Printer object
        assumes that the document data is in the format defined by the
        Printer object's "document-format-default" attribute.  If the
        client supplies this attribute, but the value is not supported
        by the Printer object, i.e., the value is not one of the values
        of the Printer object's "document-format-supported" attribute,
        the Printer object MUST reject the request and return the '
        client-error-document-format-not-supported' status code.

     "document-natural-language" (naturalLanguage):
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute. This attribute
        specifies the natural language of the document for those
        document-formats that require a specification of the natural
        language in order to image the document unambiguously. There are
        no particular values required for the Printer object to support.

     "compression" (type3 keyword)
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute and the "compression-
        supported" attribute (see section 4.4.29).  The client supplied
        "compression" operation attribute identifies the compression
        algorithm used on the document data.  If the client omits this
        attribute, the Printer object MUST assume that the data is not
        compressed.  If the client supplies the attribute and the
        Printer object supports the attribute, the Printer object uses
        the corresponding decompression algorithm on the document data.
        If the client supplies this attribute, but the value is not
        supported by the Printer object, i.e., the value is not one of
        the values of the Printer object's "compression-supported"
        attribute, the Printer object MUST copy the attribute and its
        value to the Unsupported Attributes response group, reject the
        request, and return the 'client-error-attributes-or-values-not-
        supported' status code.

     "job-k-octets" (integer(0:MAX))
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute and the "job-k-
        octets-supported" attribute (see section 4.4.30).  The client
        supplied "job-k-octets" operation attribute identifies the total
        size of the document(s) in K octets being submitted (see section
        4.3.17 for the complete semantics).  If the client supplies the

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        attribute and the Printer object supports the attribute, the
        value of the attribute is used to populate the Job object's
        "job-k-octets" Job Description attribute.

        Note: For this attribute and the following two attributes
        ("job-impressions", and "job-media-sheets"), if the client
        supplies the attribute, but the Printer object does not support
        the attribute, the Printer object ignores the client-supplied
        value.  If the client supplies the attribute and the Printer
        supports the attribute, and the value is within the range of the
        corresponding Printer object's "xxx-supported" attribute, the
        Printer object MUST use the value to populate the Job object's
        "xxx" attribute.  If the client supplies the attribute and the
        Printer supports the attribute, but the value is outside the
        range of the corresponding Printer object's "xxx-supported"
        attribute, the Printer object MUST copy the attribute and its
        value to the Unsupported Attributes response group, reject the
        request, and return the 'client-error-attributes-or-values-not-
        supported' status code.  If the client does not supply the
        attribute, the Printer object MAY choose to populate the
        corresponding Job object attribute depending on whether the
        Printer object supports the attribute and is able to calculate
        or discern the correct value.

     "job-impressions" (integer(0:MAX))
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute and the "job-
        impressions-supported" attribute (see section 4.4.31).  The
        client supplied "job-impressions" operation attribute identifies
        the total size in number of impressions of the document(s) being
        submitted (see section 4.3.18 for the complete semantics).

        See note under "job-k-octets".

     "job-media-sheets" (integer(0:MAX))
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute and the "job-media-
        sheets-supported" attribute (see section 4.4.32).  The client
        supplied "job-media-sheets" operation attribute identifies the
        total number of media sheets to be produced for this job (see
        section 4.3.19 for the complete semantics).

        See note under "job-k-octets".

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   Group 2: Job Template Attributes

        The client OPTIONALLY supplies a set of Job Template attributes
        as defined in section 4.2.  If the client is not supplying any
        Job Template attributes in the request, the client SHOULD omit
        Group 2 rather than sending an empty group.  However, a Printer
        object MUST be able to accept an empty group.

   Group 3: Document Content

        The client MUST supply the document data to be processed.

   Note: In addition to the MANDATORY parameters required for every
   operation request, the simplest Print-Job Request consists of just
   the "attributes-charset" and "attributes-natural-language" operation
   attributes; the "printer-uri" target operation attribute; the
   Document Content and nothing else.  In this simple case, the Printer
   object:

     - creates a new Job object (the Job object contains a single
       document),
     - stores a generated Job name in the "job-name" attribute in the
       natural language and charset requested (see Section 3.1.4.1) (if
       those are supported, otherwise using the Printer object's default
       natural language and charset), and
     - at job processing time, uses its corresponding default value
       attributes for the supported Job Template attributes that were
       not supplied by the client as IPP attribute or embedded
       instructions in the document data.

3.2.1.2 Print-Job Response

       The Printer object MUST return to the client the following sets
       of attributes as part of the Print-Job Response:

       Group 1: Operation Attributes

     Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text) operation attribute as described in sections 14 and
        3.1.6.  If the client supplies unsupported or conflicting Job
        Template attributes or values, the Printer object MUST reject or
        accept the Print-Job request depending on the whether the client
        supplied a 'true' or 'false' value for the "ipp-attribute-
        fidelity" operation attribute.  See the Implementer's Guide
        [ipp-iig] for a complete description of the suggested steps for
        processing a create request.

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     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

        This is a set of Operation and Job Template attributes supplied
        by the client (in the request) that are not supported by the
        Printer object or that conflict with one another (see the
        Implementer's Guide [ipp-iig]).  If the Printer object is not
        returning any Unsupported Attributes in the response, the
        Printer object SHOULD omit Group 2 rather than sending an empty
        group.  However, a client MUST be able to accept an empty group.

        Unsupported attributes fall into three categories:

        1. The Printer object does not support the supplied attribute
           (no matter what the attribute syntax or value).
        2. The Printer object does support the attribute, but does not
           support some or all of the particular attribute syntaxes or
           values supplied by the client (i.e., the Printer object does
           not have those attribute syntaxes or values in its
           corresponding "xxx-supported" attribute).
        3. The Printer object does support the attributes and values
           supplied, but the particular values are in conflict with one
           another, because they violate a constraint, such as not being
           able to staple transparencies.

        In the case of an unsupported attribute name, the Printer object
        returns the client-supplied attribute with a substituted "out-
        of-band" value of 'unsupported' indicating no support for the
        attribute itself (see the beginning of section 4.1).

        In the case of a supported attribute with one or more
        unsupported attribute syntaxes or values, the Printer object
        simply returns the client-supplied attribute with the
        unsupported attribute syntaxes or values as supplied by the
        client.  This indicates support for the attribute, but no
        support for that particular attribute syntax or value.  If the
        client supplies a multi-valued attribute with more than one
        value and the Printer object supports the attribute but only
        supports a subset of the client-supplied attribute syntaxes or
        values, the Printer object MUST return only those attribute
        syntaxes or values that are unsupported.

        In the case of two (or more) supported attribute values that are
        in conflict with one another (although each is supported
        independently, the values conflict when requested together

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        within the same job), the Printer object MUST return all the
        values that it ignores or substitutes to resolve the conflict,
        but not any of the values that it is still using.  The choice
        for exactly how to resolve the conflict is implementation
        dependent.  See The Implementer's Guide [ipp-iig] for an
        example.

        In these three cases, the value of the "ipp-attribute-fidelity"
        supplied by the client does not affect what the Printer object
        returns.  The value of "ipp-attribute-fidelity" only affects
        whether the Print-Job operation is accepted or rejected.  If the
        job is accepted, the client may query the job using the Get-
        Job-Attributes operation requesting the unsupported attributes
        that were returned in the create response to see which
        attributes were ignored (not stored on the Job object) and which
        attributes were stored with other (substituted) values.

   Group 3: Job Object Attributes

     "job-uri" (uri):
        The Printer object MUST return the Job object's URI by returning
        the contents of the REQUIRED "job-uri" Job object attribute.
        The client uses the Job object's URI when directing operations
        at the Job object.  The Printer object always uses its
        configured security policy when creating the new URI.  However,
        if the Printer object supports more than one URI, the Printer
        object also uses information about which URI was used in the
        Print-Job Request to generated the new URI so that the new URI
        references the correct access channel.  In other words, if the
        Print-Job Request comes in over a secure channel, the Printer
        object MUST generate a Job URI that uses the secure channel as
        well.

     "job-id" (integer(1:MAX)):
        The Printer object MUST return the Job object's Job ID by
        returning the REQUIRED "job-id" Job object attribute.  The
        client uses this "job-id" attribute in conjunction with the
        "printer-uri" attribute used in the Print-Job Request when
        directing Job operations at the Printer object.

     "job-state":
        The Printer object MUST return the Job object's REQUIRED "job-
        state" attribute. The value of this attribute (along with the
        value of the next attribute "job-state-reasons") is taken from a
        "snapshot" of the new Job object at some meaningful point in
        time (implementation defined) between when the Printer object
        receives the Print-Job Request and when the Printer object
        returns the response.

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     "job-state-reasons":
        The Printer object OPTIONALLY returns the Job object's OPTIONAL
        "job-state-reasons" attribute.  If the Printer object supports
        this attribute then it MUST be returned in the response.  If
        this attribute is not returned in the response, the client can
        assume that the "job-state-reasons" attribute is not supported
        and will not be returned in a subsequent Job object query.

     "job-state-message":
        The Printer object OPTIONALLY returns the Job object's OPTIONAL
        "job-state-message" attribute.  If the Printer object supports
        this attribute then it MUST be returned in the response.  If
        this attribute is not returned in the response, the client can
        assume that the "job-state-message" attribute is not supported
        and will not be returned in a subsequent Job object query.

     "number-of-intervening-jobs":
        The Printer object OPTIONALLY returns the Job object's OPTIONAL
        "number-of-intervening-jobs" attribute.  If the Printer object
        supports this attribute then it MUST be returned in the
        response.  If this attribute is not returned in the response,
        the client can assume that the "number-of-intervening-jobs"
        attribute is not supported and will not be returned in a
        subsequent Job object query.

        Note: Since any printer state information which affects a job's
        state is reflected in the "job-state" and "job-state-reasons"
        attributes, it is sufficient to return only these attributes and
        no specific printer status attributes.

   Note: In addition to the MANDATORY parameters required for every
   operation response, the simplest response consists of the just the
   "attributes-charset" and "attributes-natural-language" operation
   attributes and the "job-uri", "job-id", and "job-state" Job Object
   Attributes.  In this simplest case, the status code is "successful-
   ok" and there is no "status-message" operation attribute.

3.2.2 Print-URI Operation

   This OPTIONAL operation is identical to the Print-Job operation
   (section 3.2.1) except that a client supplies a URI reference to the
   document data using the "document-uri" (uri) operation attribute (in
   Group 1) rather than including the document data itself.  Before
   returning the response, the Printer MUST validate that the Printer
   supports the retrieval method (e.g., http, ftp, etc.) implied by the
   URI, and MUST check for valid URI syntax.  If the client-supplied URI
   scheme is not supported, i.e. the value is not in the Printer
   object's "referenced-uri-scheme-supported" attribute, the Printer

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   object MUST reject the request and return the 'client-error-uri-
   scheme-not-supported' status code.  See The Implementer's Guide
   [ipp-iig] for suggested additional checks.  The Printer NEED NOT
   follow the reference and validate the contents of the reference.

   If the Printer object supports this operation, it MUST support the
   "reference-uri-schemes-supported" Printer attribute (see section
   4.4.24).

   It is up to the IPP object to interpret the URI and subsequently
   "pull" the document from the source referenced by the URI string.

3.2.3 Validate-Job Operation

   This REQUIRED operation is similar to the Print-Job operation
   (section 3.2.1) except that a client supplies no document data and
   the Printer allocates no resources (i.e., it does not create a new
   Job object).  This operation is used only to verify capabilities of a
   printer object against whatever attributes are supplied by the client
   in the Validate-Job request.  By using the Validate-Job operation a
   client can validate that an identical Print-Job operation (with the
   document data) would be accepted. The Validate-Job operation also
   performs the same security negotiation as the Print-Job operation
   (see section 8), so that a client can check that the client and
   Printer object security requirements can be met before performing a
   Print-Job operation.

   Note: The Validate-Job operation does not accept a "document-uri"
   attribute in order to allow a client to check that the same Print-URI
   operation will be accepted, since the client doesn't send the data
   with the Print-URI operation.  The client SHOULD just issue the
   Print-URI request.

   The Printer object returns the same status codes, Operation
   Attributes (Group 1) and Unsupported Attributes (Group 2) as the
   Print-Job operation.  However, no Job Object Attributes (Group 3) are
   returned, since no Job object is created.

3.2.4 Create-Job Operation

   This OPTIONAL operation is similar to the Print-Job operation
   (section 3.2.1) except that in the Create-Job request, a client does
   not supply document data or any reference to document data.  Also,
   the client does not supply any of the "document-name", "document-
   format", "compression", or "document-natural-language" operation
   attributes.  This operation is followed by one or more Send-Document
   or Send-URI operations.  In each of those operation requests, the

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   client OPTIONALLY supplies the "document-name", "document-format",
   and "document-natural-language" attributes for each document in the
   multi-document Job object.

   If a Printer object supports the Create-Job operation, it MUST also
   support the Send-Document operation and also MAY support the Send-URI
   operation.

   If the Printer object supports this operation, it MUST support the
   "multiple-operation-time-out" Printer attribute (see section 4.4.28).


3.2.5 Get-Printer-Attributes Operation

   This REQUIRED operation allows a client to request the values of the
   attributes of a Printer object.   In the request, the client supplies
   the set of Printer attribute names and/or attribute group names in
   which the requester is interested.  In the response, the Printer
   object returns a corresponding attribute set with the appropriate
   attribute values filled in.

   For Printer objects, the possible names of attribute groups are:

     - 'job-template': all of the Job Template attributes that apply to
       a Printer object (the last two columns of the table in Section
       4.2).
     - 'printer-description': the attributes specified in Section 4.4.
     - 'all': the special group 'all' that includes all supported
       attributes.

   Since a client MAY request specific attributes or named groups, there
   is a potential that there is some overlap.  For example, if a client
   requests, 'printer-name' and 'all', the client is actually requesting
   the "printer-name" attribute twice: once by naming it explicitly, and
   once by inclusion in the 'all' group.  In such cases, the Printer
   object NEED NOT return each attribute only once in the response even
   if it is requested multiple times.  The client SHOULD NOT request the
   same attribute in multiple ways.

   It is NOT REQUIRED that a Printer object support all attributes
   belonging to a group (since some attributes are OPTIONAL).  However,
   it is REQUIRED that each Printer object support all group names.

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3.2.5.1 Get-Printer-Attributes Request

   The following sets of attributes are part of the Get-Printer-
   Attributes Request:

   Group 1: Operation Attributes

     Natural Language and Character Set:
        attributes-charset" and "attributes-natural-language" butes as
        described in section 3.1.4.1.

     Target:
        The "printer-uri" (uri) operation attribute which is the target
        for this operation as described in section 3.1.5.

     Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.

     "requested-attributes" (1setOf keyword) :
        The client OPTIONALLY supplies a set of attribute names and/or
        attribute group names in whose values the requester is
        interested.  The Printer object MUST support this attribute.  If
        the client omits this attribute, the Printer MUST respond as if
        this attribute had been supplied with a value of 'all'.

     "document-format" (mimeMediaType) :
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  This attribute is useful
        for a Printer object to determine the set of supported attribute
        values that relate to the requested document format.  The
        Printer object MUST return the attributes and values that it
        uses to validate a job on a create or Validate-Job operation in
        which this document format is supplied. The Printer object
        SHOULD return only (1) those attributes that are supported for
        the specified format and (2) the attribute values that are
        supported for the specified document format.  By specifying the
        document format, the client can get the Printer object to
        eliminate the attributes and values that are not supported for a
        specific document format.  For example, a Printer object might
        have multiple interpreters to support both '
        application/postscript' (for PostScript) and 'text/plain' (for
        text) documents.  However, for only one of those interpreters
        might the Printer object be able to support "number-up" with
        values of '1', '2', and '4'.  For the other interpreter it might
        be able to only support "number-up" with a value of '1'. Thus a

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        client can use the Get-Printer-Attributes operation to obtain
        the attributes and values that will be used to accept/reject a
        create job operation.

        If the Printer object does not distinguish between different
        sets of supported values for each different document format when
        validating jobs in the create and Validate-Job operations, it
        MUST NOT distinguish between different document formats in the
        Get-Printer-Attributes operation. If the Printer object does
        distinguish between different sets of supported values for each
        different document format specified by the client, this
        specialization applies only to the following Printer object
        attributes:

       - Printer attributes that are Job Template attributes ("xxx-
          default" "xxx-supported", and "xxx-ready" in the Table in
          Section 4.2),
       - "pdl-override-supported",
       - "compression-supported",
       - "job-k-octets-supported",
       - "job-impressions-supported,
       - "job-media-sheets-supported"
       - "printer-driver-installer",
       - "color-supported", and
       - "reference-uri-schemes-supported"

        The values of all other Printer object attributes (including
        "document-format-supported") remain invariant with respect to
        the client supplied document format (except for new Printer
        description attribute as registered according to section 6.2).

        If the client omits this "document-format" operation attribute,
        the Printer object MUST respond as if the attribute had been
        supplied with the value of the Printer object's "document-
        format-default" attribute.  It is recommended that the client
        always supply a value for "document-format", since the Printer
        object's "document-format-default" may be 'application/octet-
        stream', in which case the returned attributes and values are
        for the union of the document formats that the Printer can
        automatically sense.  For more details, see the description of
        the 'mimeMediaType' attribute syntax in section 4.1.9.

        If the client supplies a value for the "document-format"
        Operation attribute that is not supported by the Printer, i.e.,
        is not among the values of the Printer object's "document-
        format-supported" attribute, the Printer object MUST reject the
        operation and return the 'client-error-document-format-not-
        supported' status code.

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3.2.5.2 Get-Printer-Attributes Response

   The Printer object returns the following sets of attributes as part
   of the Get-Printer-Attributes Response:

   Group 1: Operation Attributes

     Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text) operation attribute as described in section 3.1.6.

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

        This is a set of Operation attributes supplied by the client (in
        the request) that are not supported by the Printer object or
        that conflict with one another (see sections 3.2.1.2 and 16).
        The response NEED NOT contain the "requested-attributes"
        operation attribute with any supplied values (attribute
        keywords) that were requested by the client but are not
        supported by the IPP object.  If the Printer object is not
        returning any Unsupported Attributes in the response, the
        Printer object SHOULD omit Group 2 rather than sending an empty
        group.  However, a client MUST be able to accept an empty group.

   Group 3: Printer Object Attributes

        This is the set of requested attributes and their current
        values.  The Printer object ignores (does not respond with) any
        requested attribute which is not supported.  The Printer object
        MAY respond with a subset of the supported attributes and
        values, depending on the security policy in force.  However, the
        Printer object MUST respond with the 'unknown' value for any
        supported attribute (including all REQUIRED attributes) for
        which the Printer object does not know the value.  Also the
        Printer object MUST respond with the 'no-value' for any
        supported attribute (including all REQUIRED attributes) for
        which the system administrator has not configured a value.  See
        the description of the "out-of-band" values in the beginning of
        Section 4.1.

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3.2.6 Get-Jobs Operation

   This REQUIRED operation allows a client to retrieve the list of Job
   objects belonging to the target Printer object.  The client may also
   supply a list of Job attribute names and/or attribute group names.  A
   group of Job object attributes will be returned for each Job object
   that is returned.

   This operation is similar to the Get-Job-Attributes operation, except
   that this Get-Jobs operation returns attributes from possibly more
   than one object (see the description of Job attribute group names in
   section 3.3.4).

3.2.6.1 Get-Jobs Request

   The client submits the Get-Jobs request to a Printer object.

   The following groups of attributes are part of the Get-Jobs Request:

   Group 1: Operation Attributes

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.1.

     Target:
        The "printer-uri" (uri) operation attribute which is the target
        for this operation as described in section 3.1.5.

     Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.

     "limit" (integer(1:MAX)):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute. It is an integer value that
        indicates a limit to the number of Job objects returned.  The
        limit is a "stateless limit" in that if the value supplied by
        the client is 'N', then only the first 'N' jobs are returned in
        the Get-Jobs Response.  There is no mechanism to allow for the
        next 'M' jobs after the first 'N' jobs.  If the client does not
        supply this attribute, the Printer object responds with all
        applicable jobs.

     "requested-attributes" (1setOf keyword):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  It is a set of Job
        attribute names and/or attribute groups names in whose values

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        the requester is interested.  This set of attributes is returned
        for each Job object that is returned.  The allowed attribute
        group names are the same as those defined in the Get-Job-
        Attributes operation in section 3.3.4.  If the client does not
        supply this attribute, the Printer MUST respond as if the client
        had supplied this attribute with two values:  'job-uri' and '
        job-id'.

     "which-jobs" (type2 keyword):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  It indicates which Job
        objects MUST be returned by the Printer object. The values for
        this attribute are:

          'completed': This includes any Job object whose state is
             'completed', 'canceled', or 'aborted'.
          'not-completed': This includes any Job object whose state is '
             pending', 'processing', 'processing-stopped', or 'pending-
             held'.

        A Printer object MUST support both values.  However, if the
        mentation does not keep jobs in the 'completed', 'canceled', '
        aborted' states, then it returns no jobs when the 'completed'
        value is supplied.

        If a client supplies some other value, the Printer object MUST
        copy the attribute and the unsupported value to the Unsupported
        Attributes response group, reject the request, and return the '
        client-error-attributes-or-values-not-supported' status code.

        If the client does not supply this attribute, the Printer object
        MUST respond as if the client had supplied the attribute with a
        value of 'not-completed'.

     "my-jobs" (boolean):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  It indicates whether all
        jobs or just the jobs submitted by the requesting user of this
        request  MUST be returned by the Printer object.  If the client
        does not supply this attribute, the Printer object MUST respond
        as if the client had supplied the attribute with a value of '
        false', i.e., all jobs.  The means for authenticating the
        requesting user and matching the jobs is described in section 8.

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3.2.6.2 Get-Jobs Response

   The Printer object returns all of the Job objects that match the
   criteria as defined by the attribute values supplied by the client in
   the request.  It is possible that no Job objects are returned since
   there may literally be no Job objects at the Printer, or there may be
   no Job objects that match the criteria supplied by the client.  If
   the client requests any Job attributes at all, there is a set of Job
   Object Attributes returned for each Job object.

   Group 1: Operation Attributes

     Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text) operation attribute as described in sections 14 and
        3.1.6.

     Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

        This is a set of Operation attributes supplied by the client (in
        the request) that are not supported by the Printer object or
        that conflict with one another (see sections 3.2.1.2 and the
        Implementer's Guide [ipp-iig]).  The response NEED NOT contain
        the "requested-attributes" operation attribute with any supplied
        values (attribute keywords) that were requested by the client
        but are not supported by the IPP object.  If the Printer object
        is not returning any Unsupported Attributes in the response, the
        Printer object SHOULD omit Group 2 rather than sending an empty
        group.  However, a client MUST be able to accept an empty group.

   Groups 3 to N: Job Object Attributes

        The Printer object responds with one set of Job Object
        Attributes for each returned Job object.  The Printer object
        ignores (does not respond with) any requested attribute or value
        which is not supported or which is restricted by the security
        policy in force, including whether the requesting user is the
        user that submitted the job (job originating user) or not (see
        section 8).  However, the Printer object MUST respond with the '
        unknown' value for any supported attribute (including all
        REQUIRED attributes) for which the Printer object does not know

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        the value, unless it would violate the security policy.  See the
        description of the "out-of-band" values in the beginning of
        Section 4.1.

        Jobs are returned in the following order:

          - If the client requests all 'completed' Jobs (Jobs in the '
            completed', 'aborted', or 'canceled' states), then the Jobs
            are returned newest to oldest (with respect to actual
            completion time)
          - If the client requests all 'not-completed' Jobs (Jobs in the
            'pending', 'processing', 'pending-held', and 'processing-
            stopped' states), then Jobs are returned in relative
            chronological order of expected time to complete (based on
            whatever scheduling algorithm is configured for the Printer
            object).



(page 50 continued on part 3)

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