The trick is that all explicitly whitelisted sites need to be at the top of the Exceptions list. That or before the blocked Content Filter categories.
1. In the Block/Accept page, go to Custom Categories.
2. Create a Custom Category. Give it a Category name. In the “Domains to be included put in the url’s to be whitelisted. So that would be:
*.hyatt.com
lillytremont.com
columbus.regency.hyatt.com
hyatt.com
Click Add.
3. Go to Exceptions. In the Add Exception. Click Allow. In the “Applies To:” choose All Users. In the “Exception Type:” choose Content Filter. In the “Sub Category:” choose the Custom Categories section and the new one you made (in this case Hotels). Click Add.
4. No move that rule all the way to the top or before any blocked Content Filter rules. This is key to allow custom URL’s to be Whitelisted.