Java Language Specification

I've been reading the Java Language Specification to improve my knowledge of the Java language. Here's a list of things I've learned:

$ identifier

The $ character can be part of a Java identifier. "for historical reasons, the ASCII underscore (_, or \u005f) and dollar sign ($, or \u0024). The $ character should be used only in mechanically generated source code or, rarely, to access preexisting names on legacy systems."

This means I can make my Java programs look like Perl. <geshi lang="java5"> int $$;String $0="$",$; void $(){if($$==0)System.out.println($0!=$?$0:$);} </geshi>