This may be old news, but it is new to me. Yahoo! has its own simplified version of being able to submit a sitemap to them for crawling and indexing. On their How to Submit help page at https://submit.search.yahoo.com/free/request, they say "You can also provide the location of a text file containing a list of URLs, one URL per line, say urllist.txt. We also recognize compressed versions of the file, say urllist.gz." Cool.