User Name Caption

[JahReefster]

I've noticed that on the left margin of one's posts, under the user name and above the avatar, there is usually a descriptive phrase such as "Registered Member,", "Premium Member," "RC Staff," etc. However, some captions seem to be customized, with whimsical sayings, species names, etc. How is this done? I've checked out the edit profile options and can't seem to find out.

Thanks.