[JarryShaw]

• Searched for similar pull requests
• Followed the coding style
• make test passes, and a test case covers the change
• Changelog entry: N/A — centralised in docs(changelog): shared 1.5.0 changelog — long-lived, merges last (#610, #616, #617, #618, #620) #657

What is the purpose of your pull request?

• docs — documentation only

---

Description

Closes #2316, as #1016 ruled.

• Fix:
  • Link.register, Internet.register and Transport.register now name ProtocolBase in Raises:, matching the ProtocolBase, SCTP, Frame and PCAPNG sites. So does the ProtocolBase.__proto__ #: comment.
  • The error message still names Protocol.
• Test: test_register_class_guard_unit gains two checks: every register site's Raises: names ProtocolBase, and the __proto__ comments say ProtocolBase subclass.
• Fail-without-fix: on origin/main, 5 failed (Link, Internet, TCP, UDP, protocol.py).
• Prose only: docstrings and comments in the library files; code_of reports all four as docs-only.

[JarryShaw]

Review: GOOD TO GO at e6aec8ad2 (Sonnet).

• Raises: sections: every register that reaches _next_layer_entry now names ProtocolBase: Link, Internet, Transport, ProtocolBase (both blocks), SCTP, Frame and PCAPNG. The __proto__ #: comment does too.
• Error message: it still says Protocol (fix(foundation): registrar error messages and type hints name the public class, not the Base the guard checks #1016).
• Library diff: docstrings and comments only. An AST dump of all four files, with docstrings blanked, matches origin/main.
• Fail-without-fix: on origin/main, 5 failed (Link, Internet, TCP and UDP Raises, plus the __proto__ comment). On the head, 149 passed.
• Non-blocking: the Raises guard covers Link, Internet, TCP and UDP. SCTP, ProtocolBase, Frame and PCAPNG are correct today but not pinned.

[github-actions]

Coverage: 91.56% (unit tier, Python 3.15, e6aec8ad2, Unit Tests run success)

Package	Statements	Missed	Branches	Partial	Cover
pcapkit (top level)	104	4	20	2	95.16%
pcapkit/const	19599	881	2618	867	92.11%
pcapkit/corekit	2589	74	816	37	96.51%
pcapkit/dumpkit	282	3	102	3	98.44%
pcapkit/foundation	3023	23	1044	25	98.82%
pcapkit/interface	138	4	52	3	96.32%
pcapkit/protocols	17437	218	4586	185	98.15%
pcapkit/toolkit	869	36	298	10	95.20%
pcapkit/utilities	504	7	146	5	98.15%
pcapkit/vendor	4432	1988	1018	167	51.87%

Per-file detail: the coverage-html artifact of this run.

[JarryShaw]

Ready to merge at e6aec8ad2. Closes #2316.

• Review: GOOD TO GO (Sonnet).
• CI: every check passed, Required checks passed included. The experimental legs are green, and KTLO shows no warnings.
• Ordering leg: protocols gave 1944 tests with 0 failures, run with the PR merged into 2d8c8b516.
• Merge state: mergeable. It is BEHIND only because of main's test-only pushes since then, and no file overlaps.