I noticed that some badges (such as Nice Answer: Answer score of 10 or more) are awarded each time the threshold is reached, but others (such as Mortarboard: Earned at least 200 reputation in a single day) are only awarded once. Is there any particular reason for the two modes, or is it merely arbitrary? (Maybe Mortarboard badges are awarded only once, because of the Epic badge? "Earned 200 daily reputation 50 times").
For consistency purposes, if the Mortarboard badge is awarded only once, perhaps its explanation should be changed to: "First time reaching 200 points in a single day," (which would mirror, say, Supporter: "First up vote").
To clarify, I'm not griping - I'm merely curious, as a trained software engineer. At first, I thought maybe I had unearthed a bug; on second thought, I think it's simply a matter of an ambiguous explanation. I realize this is a trivial and inconsequential matter, but these are the kinds of things I sometimes notice and wonder about.