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"
V15.1.0 (Wzip)
2018/03 125 p.
essential Table of Contents for TR 33.880 Word version: 15.1.0
each title, in the "available" or "not available yet" area, links to the equivalent title in the CONTENT