Capital Letter is a friend of Mr. Period. He is a part of the punctuation gang. He is a capital letter with eyes and a mouth.
He reappeared during Mr. Period's help with Johnathan Gabriel's letter to Japan.
His third return was not a happy one. He grew ever annoyed and even pissed off at the Dollar Sign for being somewhere where he is not wanted. He told the Dollar Sign to "fuck off and die" as "no-one wants [him] here".