When looking at sports fitted hats, what does "DH" and "ZH" mean ?

ZH description: "Features 97% acrylic 3% spandex Raised embroidered team graphic on the crown 6 panel ZH cap has 6 eyelets that allow your head to breathe Adjustable cap features a spandex band for a fitted look that stretches to fit your head." - <a rel="nofollow" href="http://www.shop.com/Zephyr_Georgia_Bulldogs_ZH_Fitted_Hat_-6714396-o!.shtml?trk=10&buy=0">http://www.shop.com/Zephyr_Georgia_Bulldogs_ZH_Fitted_Hat_-6714396-o!.shtml?trk=10&buy=0</a> DH description: The officially licensed DH Fitted hat from Zephyr is designed with the traditional raised embroidered team logo on the crown, and made with a long-lasting wool design. Features: Fitted wool cap Team colored crown, visor, button and eyelets Traditional raised embroidered logo on the crown Decorated in the team colors Officially licensed Imported - <a rel="nofollow" href="http://www.buy.com/prod/zephyr-long-beach-st-dh-fitted-hat/q/loc/17250/201972847.html">http://www.buy.com/prod/zephyr-long-beach-st-dh-fitted-hat/q/loc/ ...  more