Yahoo sitemaps are simple in format and powerful for ranking!

Yahoo sitemaps started out as simple text file sitemaps. Yahoo has expanded to accept RSS and ROR sitemaps, but the original format was a text-only file using one URL per line. The typical naming for this file, as suggested by Yahoo, is urllist.txt which pretty much describes what it is and what it does for them.
Yahoo site maps
The Yahoo format also makes an easy way for you to import it into your database for stats or into your spreadsheet software. It is an easy format for a human to look at and review what your URLs look like on the grand scale.
Yahoo site maps