lucy24 - 2:10 am on Oct 11, 2011 (gmt 0)
If you're submitting it manually to gwt or listing it in your robots.txt you can probably call it just about anything. If you want search engines to find it by blind luck, better stick with sitemap.txt. Or sitemap.xml.
https://www.google.com/support/webmasters/bin/answer.py?answer=183668 * sez
For best results, follow these guidelines:
* You must fully specify URLs, as Google attempts to crawl them exactly as provided.
* The text file must use UTF-8 encoding.
* The text file should contain nothing but the list of URLs.
* You can name the text file anything you wish. Google recommends giving the file a .txt extension (for instance, sitemap.txt).
If you are based in a country that uses Roman script you can ignore the UTF-8 business, because your URLs will naturally not include any non-ASCII characters. (Titles, sure. Filenames, nuh-uh.)
* I checked in a different browser because I got the URL from "inside". You don't have to be signed in to GWT to see the page. And I have no idea why it didn't obfuscate :(