An exclamation mark or exclamation point is a punctuation mark: ! It is usually used after an interjection or exclamation to indicate strong feelings or high volume, and generally marks the end of a sentence. A sentence ending in an exclamation mark is either an actual exclamation (“Wow!”, “Boo!”), a command (“Stop!”), or is intended to be astonishing in some way (“They were the footprints of a gigantic hound!”). In typesetting or printing the exclamation mark is called a screamer or bang. “Bang” is also common in computer programming slang. Less common names in publishing include “gasper” and “startler”.