"I don't understand the purpose of the (*FAIL) operator" --
AnomalousMonk.
It has the same purpose as zero in separated regex example. It allows '||' or '|' be written before first conditional. And then all conditionals have the same line-format. For me it is more readable :)
It is similar to:
if( 0 ){ ; }
elsif( condition_1 ){ ... }
elsif( condition_2 ){ ... }
elsif( condition_3 ){ ... }
...which is sometimes a bit more readable. Also then I can easily change the sequence of conditions by only swapping lines (including the line with the first condition).