8 From a document number to a published version

8.1 What a change request is

A published specification is never edited freely. Every alteration arrives as its own document: one problem, the clauses it affects, and the replacement paragraphs, written so that whoever applies it has no judgement left to exercise. That document is a change request, always written CR.

It is the unit of work in CT1, and the numbers say how completely. Of the 105699 CT1 documents on record ^[1], 71679 are change requests ^[2]. In the twelve months to 2026-08-04, 2835 of the 4235 documents were CRs ^{[3] [4]}.

A second kind exists for documents that are not published yet. A pCR — a proposed change to a draft — is how a specification is built before it has a version anybody has to obey. 563 arrived in the year ^[5], and 9772 over the whole record ^[6].

8.2 The trail one change leaves

TS 24.501 keeps a change history at the back, one row per version, and every row names the paperwork that produced it §Annex F. The columns are: Date, Meeting, Tdoc, CR, Rev, Cat, Subject/Comment, New version.

That table can be joined to the meeting record, and one real change traces the whole way through. Follow it once and the machinery is obvious.

S1. Somebody writes it and files it to a meeting. Nokia filed document C1-262074 to CT1 meeting C1-161, titled "Corrections related to the handling of congestion and routing failure cases when receiving CIoT user data container" C1-262074.

S2. The meeting gives it an outcome word. That document came out of C1-161 as agreed C1-262074. It was one of 174 documents to get that word at that meeting ^[7], out of 617 put to it ^[8].

S3. The change reappears in the document's own history under different paperwork. The change history of TS 24.501 carries a row dated 2026-06, with meeting CT#112, Tdoc CP-261125, CR number 7174, category F, and exactly that subject line §Annex F.

S4. A new version is published. The New version column on that row reads 20.0.0 — the version this course reads.

8.3 Two families of document number

The change history shows the handover between two bodies of paperwork, and it shows it in the column headings rather than in any sentence.

The earliest rows carry CT1's own numbers. The very first, dated 2017-10, has meeting CT1#106, Tdoc C1-174182, no CR number at all, and the comment "Draft skeleton provided by the rapporteur", producing version 0.0.0 §Annex F.

The rows just after it record p-CRs being implemented in batches, again with C1- numbers.

The rows that produced version 20.0.0 look nothing like that. Their meeting is CT#112 and their Tdoc numbers begin CP- §Annex F. Reading only the names: CT1 sits under a parent group called CT CT1 — Mobility, call control, session management (WG1_mm-cc-sm_ex-CN1), and CT is the letter in front of both the meeting name and the document numbers on those rows.

8.4 The columns nobody explains

Two columns of the change history carry information the document never defines.

Rev. Some rows have it blank, others carry 1, 2, 3, 4 or 5 §Annex F. The document gives the column a heading and never says what it counts.

The meeting record shows revision from the other side: at C1-161, 259 documents came out as revised ^[9] — more than the 174 agreed. A revision returns with a new document number, so one problem can occupy several numbers before it settles.

The register does not join a revision count to a Rev column, so those two facts sit side by side without being the same measurement.

Cat. A single letter. Rows correcting existing text carry F — including the one traced above, and rows such as "Correction to obsolete IETF RFC 8415" and "Clarification on registered for emergency services" §Annex F. A row adding something new carries a different letter: "Addition of UE Reader registration for AIoT Topology 2" is category B §Annex F.

TS 24.501 does not say anywhere what those letters stand for, and neither does the register. Read them as a grouping the paperwork uses, and do not translate them.

8.5 The other outcomes a document can get

Agreed and revised are the two big ones, but a document put to a CT1 meeting can end in six recorded ways. At C1-161 they fell out like this:

Outcome	How many
revised	259 [9]
agreed	174 [7]
postponed	70 [10]
noted	53 [11]
merged	33 [12]
withdrawn	19 [13]

Those six do not add up to the 617 documents put to the meeting ^[8].

Two further outcome words appear in the data, "approved" and "endorsed", and the register carries no count for either — so the remainder cannot be worked out by subtraction, and this course does not try.

What the register never holds is why. It knows a document's outcome word and nothing about the discussion behind it, which is one of the harder limits to work around and is listed with the rest in What this record cannot tell you.

8.6 Reading a version number

The Foreword of every 3GPP specification carries the same rule, and it is worth knowing because it tells you at a glance whether a document is safe to build against.

The number itself is three digits §Foreword:

D1. The first digit is the approval state. 1 means presented for information, 2 means presented for approval, and 3 or greater means an approved document under change control.

D2. The second digit is incremented for all changes of substance — technical enhancements, corrections, updates.

D3. The third digit is incremented when only editorial changes have gone in.

So version 0.2.2 of TS 24.501, which the change history records for 2017-12 after two rounds of editorial correction §Annex F, was a draft nobody could build against: its first digit was 0. Version 20.0.0 is an approved document under change control, because its first digit is 3 or greater.

8.7 Where the new work comes from

Not every document is a change to something.

In the twelve months to 2026-08-04, CT1 received 87 new work item descriptions ^[14], 136 new study item descriptions ^[15] and 197 discussion papers ^[16].

Those are the documents that start things rather than fix them. What they turn into over a year is The work items that fill a CT1 year, and the meeting where they are argued over is One CT1 meeting, by the numbers.