I've gone ahead and updated the license files in the avatar clothing templates and avatar model files linked in the wiki here:
http://wiki.secondlife.com/wiki/Clothing_Tutorials
The new license should correspond to http://creativecommons.org/licenses/by/3.0/legalcode
You can see a summary of the license here: http://creativecommons.org/licenses/by/3.0/
Let me know if there are any further questions or concerns!