group-expression

    Specifies the group or groups to be deleted. A group expression
    can be one or more group names, a wildcard expression, or a list
    of these separated by commas.

 remark

    Specifies a character string to be logged in the history file
    with this command, usually used to explain why the command was
    entered. The remark is enclosed in quotation marks. If no remark
    was entered, a null remark ("") is logged.