A number of modules and themes appear to be bound with an advertisement license which requires the display of the author's advertisement, and forbids its removal or modification. (It is particularly annoying that some of these advertisements embed multi-byte characters.)

Specific examples would include the
Creative Commons License
http://creativecommons.org/licenses/by-nc-sa/2.0/

and those bundled with
aqua-um
https://xoops.org/modules/library/singlefile.php?cid=1&lid=12

Xoops Avatar Maker
https://xoops.org/modules/repository/singlefile.php?cid=37&lid=1367

Am I misreading those licenses? Or, is it permissible to use such modules and themes without displaying the advertising?

{There appears to be a coding error for edits that "breaks" markup.}

When you get the source code to a module, you are free to do with that code what you want - except releasing it without the original credits and claiming it to be your own. Such are the terms of the GNU General Public License that XOOPS and all released XOOPS modules adhere to.

Hence, it is perfectly legal to remove the visible links to the module author's website and similar advertisements in the module.

:)

i'll be removing all visible copyrights from modules and themese on my new site..

not out of disprespect to the authors, far from it, they do a great job and should be acknowledged. my reason is that i think it looks un-professional having different copyright notices appear on every page a user looks at.

what i am going to do out of fairness tho, is use the 'Credits' module for that purpose and have site credits just listed in a seperate section on the site if users wish to view.. which sounds fair to me :)