Use "3GPP‑Page" to get the Word version,
and "ETSI‑search" to get the PDF version
the left border in eToC indicates whether the content is:
"available", "not available yet", or "not planned"
essential Table of Contents for TS 33.220 Word version: 16.1.0
each title, in the "available" or "not available yet" area, links to the equivalent title in the CONTENT