Forum:Copyrights question

Please I'm not english speaker so I need a quick and simple answer to a copyrights doubt. I've read in the wikipedia website the following sentence about copyrights rules:

"The rule of all the Wikipedias, including this one, is that nothing in the Wikipedia can be copyrighted by someone else. The exception is if Wikipedia editors (including named and unnamed editors) have permission to use it. This means that we are only allowed to copy things from books or from other web pages into the Wikipedia if the writer has said that anyone can copy these things and make changes to them"

Does it apply to wikia too?

I've been contacted by some admins from an external forum. they want me to copy stuff from their site and they're asking me to link to it, i guess they only want some sort of visibility on the wikia i've started. This is not the problem. The problem is they are not necessarily the authors of those pages, they are just the admins of that forum, they are granting me permission to use pages they might have not written. Plus they don't permit anyone but me to use this stuff. I don't know what to do, plus I'm not english and it does not help understanding GNU documentation and so on, please help me, i really need some tips. tyvm. ps. please forgive my poor english.

edit: i've just forgotten to say they are not the owners of that forum. It's one of those free forums from a hosting provider, so they are admins but they own nothing pubblished there.