Attributes are used to select the current scrolling display and
    to direct various types of PCA output to particular displays.
    This gives you the option of mixing or isolating different types
    of information, such as PCA input, output, diagnostic messages,
    and so on in scrollable displays.

    You can use the SELECT command with one or more qualifiers
    (/ERROR, /SOURCE, and so on) to assign one or more corresponding
    attributes to a display. If you do not specify a qualifier, the
    /SCROLL qualifier is assumed by default.

    If you use the SELECT command without specifying a display
    name, in general the attribute assignment indicated by the
    command qualifier is canceled (deselected). To reassign
    display attributes you must use another SELECT command. See the
    individual qualifier descriptions for details.