[mdlug] spamassassin regex decoded?

[Dean Durant]

Hello, is there anywhere online that some of the more
standard SA rules are decoded?  I was looking at this
one, and the 'describe' line after it tells the reader
what it is screening for.   But not all the nuts and
bolts are clear to me.   For example, what is the \x?

And the ! I thought was a forbidden metacharacter,
even though it is a valid Perl metacharacter.   

There are a lot of capital letters, too:   EBFC keep
recurring.   Is this screening for leetspeak?  
Sometimes there are numbers after the [EBFC],
sometimes letters.   Is there an easy way to
deconstruct this?       And the /i at the end, I can't
figure out what that is, either.       Thanks, Dean


Subject =~
/[s5][e3\xE8-\xEB]x[u\xB5\xF9-\xFC][a4\xE0-\xE6@][l!|1](?:[l!|1]y)?.{0,3}[e3\xE8-\xEB]xp[l!|1][i1!|l\xEC-\xEF]c[i1!|l\xEC-\xEF]t/i