X10 Subfield $x - General subdivision:

Subfield $x contains a subject subdivision that is not more appropriately contained in subfield $v (Form subdivision), $y (Chronological subdivision) or $z (Geographic subdivision).  Subfield $x is appropriate in the X10 fields only when a topical subject subdivision is added to a name or name/title heading to form an extended subject heading.

Example:

110  2#  $aLutheran Church$xClergy