anchor.diff:  a|
   The Property value is equal to any one of several values, which are separated by a
   
  -|
  -| | a|
  -pipe (|) character. See _Regular Expressions_, below, for more information.
  -
  -|
  -| | | |
  -| | | |
  +a|\|
  +a|
  +pipe (\|) character.
  +a|See _Regular Expressions_, below, for more information.
  +
   a|
   !~
   
  
positive.code: 
  a|
  The value on the left side is larger than or equal to the value on the right. Applies to
  
  |
  | | a|
  Numerical Properties only.
  
  |
  a|
  <
  
  
negative.code: Greater Than
  
  a|
  The value on the left side is larger than the value on the right. Applies to Numerical Properties only.
  
  a|
  >=
  
  