Specifies one or more classes into which newly created generations
    are to be inserted. The class expression can be a class name, a
    wildcard expression, or a list of these separated by commas. If a
    list is not used, the parentheses can be omitted.

    The new generation of each element replaced is inserted into the
    specified classes. If no new generation is created, no insertion
    takes place.

    This qualifier effectively combines the REPLACE and INSERT
    GENERATION commands. It ensures that the new generation is inserted
    into the specified class of classes, avoiding the potential problem
    of other users updating the library between a REPLACE command and a
    subsequent INSERT GENERATION command. It also deals effectively with
    variants.

    For each of the specified classes, provided there is INSERT access
    to the class and it is not set to READ_ONLY, new generations are
    always inserted, irrespective of whether or not the class already
    contains a generation of the element. Any old generation is removed
    from the class before the new generation is inserted. This is like
    using the /ALWAYS qualifier in an INSERT GENERATION command.

    If other insertion modes, for example /SUPERSEDE, are required,
    create a temporary class and use that in the REPLACE command. Then
    use the temporary class as the value of the /GENERATION qualifier in
    an INSERT GENERATION command with the required mode.

    The insert operation takes place in the library where the new
    generation was created, so class occlusion does not apply to
    classes specified in this qualifier (class occlusion applies to a
    class specified in the /GENERATION qualifier).

    Any actions specified in access control entries associated with the
    INSERT GENERATION command, or with the classes into which
    generations are inserted, will be executed after any actions
    associated with the REPLACE command or with elements being replaced.

    Use of this qualifier requires execute access to the INSERT
    GENERATION command.