The Structure Change Clause adds or modifies field, record,
    structure, and variant definitions within a structure definition.
    It removes field, record, and structure definitions.

    You cannot remove a variant definition from a structure
    definition with the Structure Change Clause. Use the Variants
    Change Clause instead.

    To add a definition within a structure definition, specify the
    Structure Change Clause, which contains an embedded Record Change
    Clause. Use the DEFINE keyword of the Record Change Clause,
    followed by the appropriate clause for the definition you are
    adding.

    For example, to add a field or record definition to the structure
    definition, specify the Included Name Clause or Local Field
    Clause. To add a structure definition, specify the Structure
    Change Clause. To add a variants definition, specify the Variants
    Change Clause.

    The definition you add becomes the last definition in the
    structure definition.

    To remove a definition from within a structure definition,
    specify the Structure Change Clause and the DELETE keyword of
    the embedded Record Change Clause, followed by the definition
    name.

                                   NOTE

       When you use the CHANGE RECORD command to change a variants
       or variant definition or an entity inside a variants
       or variant definition, you must use the Variants Change
       Clause to refer to each variants or variant definition that
       precedes the entity you are changing.