If you have an installed system, you can do a "test remove" of the package to see what packages depend on it:I was trying to figure out, for instance, why "apr" gets installed... but can't find any chaining or dependencies. And it's not named explictly in comps.xml or any of the other xml.gz files.
# rpm -q --provides apr libapr-0.so.0 apr = 0.9.4-24.5.c4.1 # rpm -e --test apr error: Failed dependencies:libapr-0.so.0 is needed by (installed) mod_perl-1.99_16-4.centos4.i386
libapr-0.so.0 is needed by (installed) apr-util-0.9.4-21.i386
libapr-0.so.0 is needed by (installed)
httpd-2.0.52-22.ent.centos4.i386
apr >= 0.9.4-24.2 is needed by (installed)
httpd-2.0.52-22.ent.centos4.i386
-Shawn