C# Language Specification

Region directives

The region directives are used to explicitly mark regions of source code.

pp-region:
pp-start-region conditional-section_opt pp-end-region

pp-start-region:
whitespace_opt # whitespace_opt region pp-message

pp-end-region:
whitespace_opt # whitespace_opt endregion pp-message

No semantic meaning is attached to a region; regions are intended for use by the programmer or by automated tools to mark a section of source code. The message specified in a #region or #endregion directive likewise has no semantic meaning; it merely serves to identify the region. Matching #region and #endregion directives may have different pp-messages.

The lexical processing of a region:

#region
...

#endregion

corresponds exactly to the lexical processing of a conditional compilation directive of the form:

#if true
...
#endif

7.