inside the 3GPP Standardization Space

in order to ease the follow-up of 5G standards
We are creating a 3GPP space with the content for most of the 3GPP technical specifications, as well as for a number of technical reports (especially the most recent studies). When this is performed, at a satisfactory level, we will develop themes.
For each 3GPP TS/TR, there is an essential table of contents (eToC) on the main page, and access to the content itself on additional pages. The left border in the eToC mentions whether the content is "available", "not available yet", or "not planned". As an alternative, for short documents, there is no eToC and the Content is displayed on the main page.
Here is a quick access to the main specifications and reports, by domain.
Tech-invite Location

3GPP Working Environment

801  Specification Drafting Rules
900  Technical Specification Group Working Methods
905  Vocabulary for 3GPP Specifications

3G-, 4G-, 5G-System: Stage 1 to Stage 3

3GPP Standardization Stage1 to Stage 3
101  Service Principles
104  Cyber-Physical Control Applications in Vertical Domains
125  Unmanned Aerial System (UAS) support in 3GPP
261  Service Requirements for the 5G System
263  Video, Imaging and Audio for Professional Applications (VIAPA)
822  Study on using Satellite Access in 5G
826  Study on Communication Services for Critical Medical Applications
003  Numbering, Addressing and Identification
008  Organization of Subscriber Data
041  CBS ‐ Cell Broadcast Service
122  NAS functions related to UE in Idle Mode
5G System
501  Architecture
502  Procedures
503  PCC (Policy and Charging Control) Framework
273  Location Services
288  Network Data Analytics Services
316  Wireless and Wireline Convergence Access Support
Mission Critical Services
280  Common Functional Architecture
281  MCVideo
282  MCData
379  MCPTT
303  ProSe
Evolved Packet System
401  Architecture & Procedures for 3GPP accesses
402  Architecture & Procedures for non-3GPP accesses
228  IMS Architecture
167  IMS Emergency Sessions
060  Architecture & Procedures for GERAN/UTRAN accesses
501  Non-Access-Stratum (NAS) Protocol for 5GS
502  Access to the 5GS via non-3GPP Access Networks
301  Non-Access-Stratum (NAS) Protocol for EPS
302  Access to the EPC via non-3GPP Access Networks
229  IP Multimedia Call Control Protocol based on SIP and SDP
500  Technical Realization of Service Based Architecture
501  5GS – Principles and Guidelines for Services Definition

3GPP Radio Access Technology (RAT) and Network (RAN)

3GPP Standardization Domain: RAT and RAN
5G New Radio
300  5G NR and NG-RAN Overall Description
304  5G NR – UE procedures in idle mode
401  NG-RAN – Architecture Description
413  NG-RAN – NGAP
423  NG-RAN – XnAP
455  NG-RAN – NRPPa
463  NG-RAN – E1AP
473  NG-RAN – F1AP

3GPP Security

3GPP Standardization Domain: Security
5G System
501  Architecture & Procedures
Lawful Interception
126  Requirements
127  Architecture and Functions
128  Handover Interface
102  3G Security Architecture

3GPP Operations, Administration and Maintenance

3GPP Standardization Domain: Operations and Maintenance
500  Management Concept, Architecture and Requirements for Mobile Networks that include Virtualized Network Functions

3GPP Media Handling, Terminal Functions, UICC/USIM/Applications

3GPP Standardization Domain: Media Handling, UICC/USIM, Terminal Functions
501  5G Media Streaming (5GMS) – General Description and Architecture
511  5G Media Streaming (5GMS) – Profiles, Codecs and Formats
007  AT Command Set for User Equipment
102  Characteristics of the Universal Subscriber Identity Module (USIM) Application