i don't know what the current etiquette is--certainly we didn't have email back in the day, lol--but we had plenty of Pi Phis dropping in, mostly from northern chapters on their way to Florida or Florida chapters on their way up north.
A particular surprise visit from some Florida State sisters sticks in my mind because I was waiting in the lobby for a date and these girls walked in and introduced themselves and just then, somebody rode a bike out of the hall and down the dorm steps, screaming, "Toot toot! Toot toot!"
Our president.