It is very easy to become a participating shelter. Just log into your account in the Worldwide Shelter Directory and check the box for the Snuggles Project. That will get you a Snuggle Kitten icon on your listing which indicates that you are a participating shelter and care about the physical and psychological comfort of the animals in your care.
If you don't have an account on the Hugs Society website, you will need to register to set that up before you will have access to add your shelter/rescue to the Worldwide Shelter Directory. Once you are on the Hugs Society website, click on Register/Login at the top of the page. Setup your name, username and password. Check your email for the activation code. Once your account is activated, click on Directory and go to the location where you would like your shelter/rescue to be listed. Click on the "Add Your Listing Here" link to begin.