In Which My Name Is Shortened

San Francisco, California, USA

Barista: "So, skinny vanilla latte?"
Me: "No! Just a skinny latte."
Barista: "You don't want a flavour?"
Me: "Just coffee flavour."
Barista: "What's your name?"
Me: "Ian."
Barista: "E. N.?"
Me: "Ian."
Barista: "Yeah, I'm just going to write 'E'."