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###  Ruleset 3 -- Name Canonicalization  ###
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Scanonify=3

# 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@ $* <@>               $: @ $1                         unmark @host:...
R$* [ IPv6 : $+ ] <@>   $: $1 [ IPv6 : $2 ]             unmark IPv6 addr
R$* :: $* <@>           $: $1 :: $2                     unmark node::addr
R:include: $* <@>       $: :include: $1                 unmark :include:...
R$* : $* [ $* ]         $: $1 : $2 [ $3 ] <@>           remark if leading colon
R$* : $* <@>            $: $2                           strip colon if marked
R$* <@>                 $: $1                           unmark
R$* ;                      $1                           strip trailing semi
R$* < $+ :; > $*        $@ $2 :; <@>                    catch <list:;>
R$* < $* ; >               $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 <>

# strip route address <@a,@b,@c:user@d> -> <user@d>
R@ $+ , $+              $2
R@ [ $* ] : $+          $2
R@ $+ : $+              $2

# find focus for list syntax
R $+ : $* ; @ $+        $@ $>Canonify2 $1 : $2 ; < @ $3 >       list syntax
R $+ : $* ;             $@ $1 : $2;                     list syntax