Also remember that some types of sites listed by LLs might well have the recip on a different page from the linked page. I allow online stores, for example, to put a link back on a "links" page...so my script needs both fields entered. I check that the link URL and the recip URL match for free sites. In many cases the scripts are designed to allow a link back from a different page, even if the LL rules state that 100% of links back must come from the page linked to.
It's also a good way to trip up the autosubmitters
