The undo command

Syntax:

Reverts the most recent changes.

The current document is returned to the state it was in before the most recent copy, delete, follow, load, precede, prefix, rename, replace, strip, suffix, transform, update, or validate command.

It will also undo the effect of:

that is, it reverts to the previous current document.

It is not possible to undo the effect of save or schema commands.