we forgot to document the "optional”/"optional-jail” pkgbase sets in freebsd-base(7) for 15.0... in case anyone is wondering, this set is everything in "base" which is not otherwise part of minimal or devel.
the use-case for this is if you want to install the complete base system without compilers, which is somewhat common on production systems with a no-compilers policy, and in jails/containers.
updated documentation: https://reviews.freebsd.org/D54065 - will land in 15.1 since this is far too trivial to errata.