"Sister!" Luna kicked the doors open, inadvertently launching the two guards standing behind them out the nearest window. They will be missed. Maybe. "I demand your name!"
Celestia blinked. "My... name? Luna, I--"
"No, sister, that's my name! What is your name?"
"Er... Celestia?"
"Well, Er Celestia," Luna held out a pen. "Would you mind writing that down? In case if I forget again."
Celestia frowned, but did so anyway, writing her name in the fanciest freakin' cursive this side of the universe.
"How am I supposed to read that?!"
"You don't!"