repo-add does removing foo.files.tar mess with the repo?

I'm curious about making a custom repo and when reading the man page, in EXAMPLE it says

repo-add foo.db.tar.xz <pkg1> [<pkg2> ...]

This creates two separate databases; a smaller database “foo.db.tar.xz” used by pacman and a large database containing package file lists “foo.files.tar.xz” for use by other utilities. While pacman can use the large database (if renamed with a db.tar* extension), there is currently no additional benefit for the larger download.

Does anyone know what these other utilities are, and it shouldn't mess with the repo if it gets removed?