man3 Documentation

Out of curiosity, I was trying to understand what man pages we generate.
I found man pgaes for the executables in man1 and a ton of documentation
in man7 related to SQL commands. The contents in man3 was a bit
perplexing. We only document a set of dblink SQL functions and a set of
SPI C functions.

Why do we document only those functions? I assume it was the wild west
(1998 and 2007) when the SGML for SPI and dblink were ported/created,
and the original authors, Thomas Lockhart[0] and Bruce[1], simply did it
because they could.

I ask because I am trying to ascertain what our policy is for
documenting functions in man3. I was thinking it could be a cool
endeavor to increase coverage, but obviously it's not worth pursuing if
it would never be committed. If we don't want to continue documenting
things in man3, should we instead remove these pages?

I did look into the mailing list a bit, and I found a thread[2] from Bear
proposing documenting libpq in man3 and man7.

[0]: https://github.com/postgres/postgres/commit/c8cfb0cea88fec22f5aa0582fe846b46baf77eb1
[1]: https://github.com/postgres/postgres/commit/c3c69ab4fd25a20749b850d34cbc8ce3f1812e3b
[2]: https://www.postgresql.org/message-id/CALBNtw4FDq_tWYErCeKO3djPEu8XHU0yKRv=5ZLUcN-FBP22tg@mail.gmail.com

--
Tristan Partin
PostgreSQL Contributors Team
AWS (https://aws.amazon.com)