acb61957__Zotonic_1_0_dev_documentation__Argument
[Description] Use when the value must be a specific length. [Example] is=4 [Argument] 
is
i s
m i n i m u m
m a x i m u m
w r o n g _ l e n g t h _ m e s s a g e
t o o _ s h o r t _ m e s s a g e
t o o _ l o n g _ m e s s a g e