Wikipedia
Swarley
"Swarley" is the seventh episode in the second season of the television series How I Met Your Mother. It originally aired on November 6, 2006.
The name Swarley is taken from an in-episode joke. A coffee shop barista mistakenly hears Barney's name as "Swarley" and writes it on his cup. This leads to a running gag in which everyone mercilessly refers to Barney as "Swarley" despite his protests. This culminates to the point of the entire bar shouting ""Swarley" when he enters, as a callback to the sitcom Cheers.