It wasn't until they crossed them sands that they were able to pick their own names. But Pledge Class name was supposed to represent something positive about that line.
My chapter had rules about the line names also. When we Ivys, we were given our line names by our big sisters and because we practice being discreet, we would NEVA be allowed to tell people those names.

When we became AKA's, we got a chance to choose our own names.

(thank GOD because, well...let's just say somethings shouldn't be repeated...