Pod::Html's cross referencing of C<> links

Hello Tom,

I am converting the homemade pod parser in Pod::Html to Pod::Simple, and I
am trying to keep most of the functionality while doing so, too.

I am currently attempting to understand how the module cross references the
links. More specifically, I understand how it resolves L<> links, but I am
confused as to why you resolve C<> "links". From reading the source, I
gather that C<> "links" are resolved by searching pod documents for =item
directives, and storing their text in a global hash.

Could you explain what C<> links are, and why you cross reference them? (You
can skip the second question if the answer to the first makes it redundant.)

Thank you,
Marc