pragmas are not even mentioned in require

Note that pragmas don't exist on the language level. That is, Perl (the language) doesn't treat modules whose name is all lowercase different from modules who do not. "Pragmas" (or as some people call them "pragmata") are a loosly defined concept; typically as 'modules that influence the compilation process in some way'. But any module that exports prototyped subroutines influences compilation. And so do source filters. Many people consider "constant.pm" to be a pragma, but all it does is export subs with an empty prototype. But Fcntl and POSIX do so as well.

Perhaps one could consider modules that set parts of @H and %H to be pragmas.