This is what my current copyright/usage rights part says on my contract:
The Contractor’s assignment is work for hire. Contractor and Photographer have a split 50/50 ownership on copyrights of images. Contractor agrees not to sell any image taken during the contracted event to any person, company, group, advertising agency, or otherwise, without Photographer’s express written permission. XXXX Photography grants Contractor permission to use the images taken during the contracted event for Contractor’s professional use in the following manner: Print portfolio and website (including but not limited to blog, Facebook, Twitter, etc.) after six (6) months from date of event. Web use shall include an accompanying “Photographed with XXXX Photography” credit line somewhere on page as well as link to XXXX website.