Taking in consideration the following example:
Originally Posted by duby229
I release 10 lines of code in two license, GPL and BSD.
If you use my 10 lines of code under GPL in your project, then you are obliged to release your project with a GPL compatible license.
BUT, if you use the same 10 lines of code released under BSD (with the related BSD license file), even if the lines are exatly the same of the GPL version, if you use the BSD version then you are not under the GPL constrains.
Of course, if you want to license your code under BSD-like license and you use my codes released under GPL, you are an idiot and you are going to violate the GPL for sure.