## 16.4 `@set`, `@clear`, and `@value`

You can direct the Texinfo formatting commands to format or ignore parts of a Texinfo file with the `@set`, `@clear`, `@ifset`, and `@ifclear` commands.

Brief descriptions:

`@set flag [value]`

  Set the variable flag, to the optional value if specifed.

`@clear flag`

  Undefine the variable flag, whether or not it was previously defined.

`@ifset flag`

  If flag is set, text through the next `@end ifset` command is formatted. If flag is clear, text through the following `@end ifset` command is ignored.

`@ifclear flag`

  If flag is set, text through the next `@end ifclear` command is ignored. If flag is clear, text through the following `@end ifclear` command is formatted.