What was not clear, because I don't took care to urls, is that because the plugins providers use quite the same logo as MantisBT.org.
So each of them presents their site as the lonely one and the applied rules as those of MantisBT.
I do believe that a way to forbid the use of a not explicit header using Mantis logo
The idea should that to allow providers and developers of plugin to use the MantisBT logo but to be obliged to add an explicit text as Plugins provided by ...
use "our MantisBT plugins ...." not "MantisBT plugins are... in their text.
This is quite clear for sites like :
- ECLIPSE and the Market place
- Mozilla and the add-ons
Although I'm not a newbie, I was confused and misled by the similarity of headers. I have looked in details and could see that these header are not exactly the same but studied copies made to mislead the user.
The best way, may be, should be to allow the use of logo but with rules and to be without pardon for misleaders (blacklist ?)