############################################
###  Ruleset 3 -- Name Canonicalization  ###
############################################
S3

# handle null input (translate to <@> special case)
R$@			$@ <@>

# strip group: syntax (not inside angle brackets!) and trailing semicolon
R$*			$: $1 <@>			mark addresses
R$* < $* > $* <@>	$: $1 < $2 > $3			unmark <addr>
R@ $* <@>		$: @ $1				unmark @host:...
R$* :: $* <@>		$: $1 :: $2			unmark node::addr
R:include: $* <@>	$: :include: $1			unmark :include:...
R$* [ $* : $* ] <@>	$: $1 [ $2 : $3 ]		unmark IPv6 addrs
R$* : $* [ $* ]		$: $1 : $2 [ $3 ] <@>		remark if leading colon
R$* : $* <@>		$: $2				strip colon if marked
R$* <@>			$: $1				unmark
R$* ;			   $1				strip trailing semi
R$* < $* ; >		   $1 < $2 >			bogus bracketed semi

# null input now results from list:; syntax
R$@			$@ :; <@>

# strip angle brackets -- note RFC733 heuristic to get innermost item
R$*			$: < $1 >			housekeeping <>
R$+ < $* >		   < $2 >			strip excess on left
R< $* > $+		   < $1 >			strip excess on right
R<>			$@ < @ >			MAIL FROM:<> case
R< $+ >			$: $1				remove housekeeping <>

# make sure <@a,@b,@c:user@d> syntax is easy to parse -- undone later
R@ $+ , $+		@ $1 : $2			change all "," to ":"

# localize and dispose of route-based addresses
R@ $+ : $+		$@ $>96 < @$1 > : $2		handle <route-addr>

# find focus for list syntax
R $+ : $* ; @ $+	$@ $>96 $1 : $2 ; < @ $3 >	list syntax
R $+ : $* ;		$@ $1 : $2;			list syntax

# find focus for @ syntax addresses
R$+ @ $+		$: $1 < @ $2 >			focus on domain
R$+ < $+ @ $+ >		$1 $2 < @ $3 >			move gaze right
R$+ < @ $+ >		$@ $>96 $1 < @ $2 >		already canonical

# do some sanity checking
R$* < @ $* : $* > $*	$1 < @ $2 $3 > $4		nix colons in addrs

# convert old-style addresses to a domain-based address
R$- ! $+		$@ $>96 $2 < @ $1 .UUCP >	resolve uucp names
R$+ . $- ! $+		$@ $>96 $3 < @ $1 . $2 >		domain uucps
R$+ ! $+		$@ $>96 $2 < @ $1 .UUCP >	uucp subdomains

# if we have % signs, take the rightmost one
R$* % $*		$1 @ $2				First make them all @s.
R$* @ $* @ $*		$1 % $2 @ $3			Undo all but the last.
R$* @ $*		$@ $>96 $1 < @ $2 >		Insert < > and finish

# else we must be a local name
R$*			$@ $>96 $1