[Zope-dev] dtml-var missing

I found an undocumented feature today- <dtml-var x missing> This displays x if x is defined (but if it is None, then the word "None" is displayed.) If x is not defined then nothing is displayed and there is no error. So, I put this in ZQR but now I am thinking - is this an undocumented feature by mistake or did you intend to deprecate it and so it is undocumented for a reason? Any other undocumented feature I should know for an important project? :) -- Stephan Richter iXL - Software Designer and Engineer CBU - Physics, Computer Science and Chemistry Student