The first link (
https://www.mobileread.com/copyright.html) goes to a page which gives some copyright guidelines concerning uploading books at mobile read, which is what I was asking about. Which is what the thread is about. Personally I think it could be made even more clear by stating "these are the rules for posting ebooks at mobile read" and then being very clear about what is acceptable and what is not. But it's certainly more clear than the previous discussion in this thread, and it's nice to know that the page exists.
One question: under Canadian law can a copyright holder extend the copyright? If so, then each book would have to be researched individually for it's current status, which was my original point. A blanket assumption that if the author has been dead for 50 years then the book is in the public domain may not be accurate.
One suggestion: make that page more readily accessible to not only people posting books but moderators trying to decide if a book is acceptable at MR. If both moderators were familiar with the page, they wouldn't have had the discussion they did in this thread. If the original poster had read it, he wouldn't have asked the question in the first place.
The second link (
https://wiki.mobileread.com/wiki/E-bo..._Public_Domain) goes to a page that talks in a generic way about copyright and public domain and in fact concentrates on US law, which, if anything, confuses the issue since apparently it's Canadian law which governs what is legal to post here.