libid3 contains a couple of zlib-related undefined non-weak symbols:

$ rpmlint id3lib
W: id3lib undefined-non-weak-symbol /usr/lib64/libid3-3.8.so.3.0.0 compress
W: id3lib undefined-non-weak-symbol /usr/lib64/libid3-3.8.so.3.0.0 uncompress

$ cat t.c
char ID3Tag_Link ();
int main ()
{
  ID3Tag_Link();
  return 0;
}

$ gcc -lid3 t.c
/usr/lib/gcc/x86_64-redhat-linux/4.1.1/../../../../lib64/libid3.so: undefined
reference to `compress'
/usr/lib/gcc/x86_64-redhat-linux/4.1.1/../../../../lib64/libid3.so: undefined
reference to `uncompress'
collect2: ld returned 1 exit status

This causes for example kid3 0.8's id3lib detection to fail (and there's no
id3lib-config script or a pkgconfig file in id3lib which could be used to
propagate -lz).