I would like to reserve UID/GID 81 for apache (www-servers/apache).

This is the historical UID/GID for apache user in Gentoo.
Fedora and RedHat use UID/GID 48. Arch Linux has no
"apache" user but a "http" user with UID/GID 33 (which is already
reserved in Gentoo).

Here are the commits for possible review:
https://github.com/Polynomial-C/gentoo/commits/accts-apache

-- 
Lars Wendler
Gentoo package maintainer
GPG: 21CC CF02 4586 0A07 ED93  9F68 498F E765 960E 9B39