3
So long as the copyright is in the source code in the form of commented code, you can remove the XOOPS copyright from your theme by editing the theme.html file. Not all themes include the XOOPS copyright and some themes carry their own copyright depending ont he authour.
There is no hard and fast rule that states you must have an XOOPS copyright on your page, although appreciated no one will hold it against you. Just be careful in how you give credit for the theme that you use, as people are a bit more sensitive on this issue.
