Invalid TAL statements

I checked the Petal and Zope docs, but couldn't find any  definitive  
answer:

how SHOULD Petal handle invalid TAL statements

by invalid i mean a 'tal:xxxx' where 'xxxx' is not a valid tal  
statement.

example:
	tal:ttributes

note  that is 'attributes' without the leading 'a'

currently Petal silently ignores these -- is this on purpose?  if  
so,  can that be added to the docs as a feature  set?  if not, can  
that forcefully throw an error?

i'm currently exploiting this 'feature' to stash away variations on  
complex string: modifier actions while i test.  its incredibly  
useful, but I'd rather not upgrade Petal one day and find a  bunch of  
test code on my templates showing.