;--
;-- Legal "natural" tags
;--

<foo bar="abc">

;-- space before > means we know it doesn't end tag
<% if 1 > 2 [print "Uh oh"] %>

;-- bar> not seen as a tag ending because it's in quotes
<foo attr="1 bar> 2" /> 

;-- <bar not seen as a tag beginning because it's in quotes
<foo attr="1 <bar 2" /> 

;-- Matched pairings
<([])>

<!-- Don't need to escape <tags> if they are naturals -->

<!-- Don't need to escape < non tags > if they aren't tags -->

;--
;-- Illegal "natural" tags...construction syntax required
;--

<foo bar="abc"    > ;-- space then > does not terminate

<   foo bar="abc"> ;-- < then space does not open a tag

<foo bar='1 bar> 2' /> ;-- single quotes aren't "super"

<foo <bar /> ;-- unclosed "foo tag", the /> closes bar.

<)][(> ;-- open/closes don't match

<([)]> ;-- improper nest

<the site is [4chan]> ;-- Rebol word rules apply in blocks

<foo bar=(if 4chan > stackoverflow [print {Uh oh.}]) baz={string}> ;-- same rules for parens