There's a doc comment in the ngAnimate source that includes a CSS @keyframes example. The '@' sign is entered as an HTML character entity so as not to conflict with doc parsing:

https://github.com/angular/angular.js/blob/master/src/ngAnimate/animate.js#L109

On the documentation page, this HTML entity does not get converted:

http://docs.angularjs.org/api/ngAnimate

Here's what it looks like:

I tried adding a semicolon and building the docs, but even then I still see the character entity not the '@' symbol.