/sys$common/syshlp/lse$help.hlb
SHOW_MAX_UNDO
 *Conan The Librarian 

  Syntax:  SHOW MAX UNDO buffer_name

  Shows the maximum number of commands that you can undo for a specific
  buffer.

  If you have not set a maximum number with the SET MAX UNDO command,
  the SHOW MAX UNDO command displays the default value of [100].

  RELATED COMMANDS:

     REDO                        UNDO
     SET MAX UNDO
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