preformatted

Preformatted text is text whose spacing and line breaks are preserved exactly as written. This mode is essential for displaying code samples, command output, configuration files, and ASCII art without reflow or reformatting.

In HTML, the pre element signals preformatted content; browsers preserve whitespace and typically render it in a fixed-width (monospace) font by default. Content inside a pre tag is displayed as written unless CSS overrides are applied. The element helps ensure that indentation, tabs, and line breaks remain intact for accurate representation.

In wiki and documentation contexts, preformatted blocks enable precise presentation of source code and data. They prevent wrapping and automatic normalization of whitespace, making alignment and indentation meaningful. Some systems also support syntax highlighting within preformatted regions to improve readability of code samples.

Creation and usage vary by platform. In HTML you use the pre element with a closing tag, for example, or rely on platform-specific blocks that emulate preformatted regions. Indentation or dedicated markup may be used to mark such blocks in wiki engines, and some environments offer explicit code block syntax for enhanced formatting and language-specific highlighting.

Limitations include that leading spaces are significant and may affect layout, and long lines can require horizontal scrolling. Because the content is not reflowed, it is important to ensure that preformatted blocks convey the intended structure clearly and remain accessible to assistive technologies when used for code or data.