uggc protocol

Links that have been ROT-13 encoded should just work. This makes http:// scheme (but not https:// yet) links work properly while encoded. The ROT-13 code is a simple Caesar cipher, where characters are shifted 13 letters (with wrap around at "Z"). The advantage of shifting 13 places is that the same operation applied twice decodes the content. ROT-13 has been a traditional internet trivial encoding method used for spoilers and other places slightly hidden text is needed for years. Now when you encounter ROT-13 links, you will be able to just follow them.

-from the Mozilla add-on page.