<if [condition_list]>doku code</if>
or <if [condition_list]>doku code<else>doku code</if>

[condition_list] is a set of [condition] records separated by logical operators (&&, and, ||, or, ^, xor for now), use of parenthesis is allowed, negation is achieved by using heading ! (ex !foo=bar or !(a=b || c<d) )

[condition] is formed from a [key], followed by an [operator] (optionnal) and then a [value] (optionnal)

[key] is in the list (defined in base_tester.php as of 2009/06/10) :
	- user : refers to the user "login" (like in $_SERVER['REMOTE_USER'])
	- group : refers to the user group-set
	- nsread : refers to the ability of the user to read a namespace
	- nsedit : refers to the ability of the user to edit a namespace
	- IP : refers to the client's IP address

[operator] signification is [key] dependent, for example :
	- = (==) : equality, membership, read/edit ability on ...
	- != : non-equality, non-member, no read/edit ability on ...
	- ...
	(browse base_tester.php for test_* methods for more information)

[value] can be a string (whitespace, ) and > free) or a " delimited string (whitespaces, ) and > are then allowed)