Here's the policy posted in the FAQ (Frequently Asked Questions):

Please remember that Mudcat is a Music Forum. We welcome discussion of all topics, but we give special emphasis to music.
If you wish to discuss other topics, you are welcome to post your own opinions. Please do not copy-paste the entire texts of lengthy non-music articles that are available elsewhere on the Internet - just post a link and summarize the article in your own words.

If you find music information or lyrics you wish to share, particularly if it is about folk music, please DO post the entire text, plus a link to where you found it.

I'd also like to ask that whenever you get information from other sources, please tell us where it came from. The Digital Tradition would be much more valuable if it had attribution for every song. We're working on adding attributions as much as we can. That's part of the reason for the DTStudy and "Origins" threads. -Joe Offer-