page_title: Exclamation mark
section_title: Warnings
hierarchical_section_title: Exclamation mark / Warnings
context_page_description: The exclamation mark, !, also sometimes referred to as the exclamation point, especially in American English, is a punctuation mark usually used after an interjection or exclamation to indicate strong feelings or high volume, or to show emphasis, and often marks the end of a sentence, for example: "Watch out!" Similarly, a bare exclamation mark is often used in warning signs.
  Other uses include:
  In mathematics it denotes the factorial operation.
  Several computer languages use! at the beginning of an expression to denote logical negation: e.g.!A means "the logical negation of A", also called "not A". This usage has spread to ordinary language.
  Some languages use! to denote a click consonant.
context_section_description: Exclamation marks are used to emphasize a precautionary statement.
  On warning signs, an exclamation mark is often used to draw attention to a warning of danger, hazards, and the unexpected. These signs are common in hazardous environments or on potentially dangerous equipment. A common type of this warning is a yellow triangle with a black exclamation mark, but a white triangle with a red border is common on European road warning signs.
caption: Warning signs are often an exclamation mark enclosed within a triangle.