<tt/(/ <em/set/ <tt/,/ <em/use/ <tt/)/, where <em/set/ is the
attribute set ordinal number and <em/use/ is the use value of the attribute.
<tag>System variable</tag> The system variables are preceded by
<tt/(/ <em/set/ <tt/,/ <em/use/ <tt/)/, where <em/set/ is the
attribute set ordinal number and <em/use/ is the use value of the attribute.
<tag>System variable</tag> The system variables are preceded by