Ath-kethin
Elder Thing
The cleric version is the standard. Bard and Druid ritual casting also works in the same way. The wizard is the exception - probably because the class is strongly associated with books, learning, and an expanded spell repertoire.
It's even more interesting, then, that the Ritual Caster feat follows the Wizard methodology, not the others.
Frankly, the Ritual Caster ability for the cleric seems extraneous at best, especially since they get more spell preparation anyway.
And I find that situation doublybironic since of you are, say, a rogue (or any other non-caster) taking the feat, the Cleric spell list is superior to the others in many respects.