This Wiki page receives the redirect for a number or windows related tokens:
Each of these text tokens return the name of the specified window.
The WindowName token takes a parameter indicating which window to use. The parameter is the value after the percent sign of the main token. For example: % WindowName%1%
The parameter may be:
So for example, %WindowName%1% gives the name of the front window.
%FrontWindowName%
is a synonym for %WindowName%Front%
and may be used interchangeably.