<para>The string returned by the external program requested with PROGRAM.
A single part of the string, separated by a space character, may be selected
by specifying the part number as an attribute: <option>%c{N}</option>.
<para>The string returned by the external program requested with PROGRAM.
A single part of the string, separated by a space character, may be selected
by specifying the part number as an attribute: <option>%c{N}</option>.