[Harry!]

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 (and therefore when spelling text out orally), 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".[1]

Exclamation marks may be repeated for additional emphasis ("That's great!!!"), but this practice is generally considered unacceptable in formal composition