modxcms/revolution — pull request #11414 by Ketziel (2014-05-27 12:37:08+00:00)
Title: Return nothing when toPlaceholder output filter is used.

Not sure if this is a bug or not, however when I used the toPlaceholder filter I expected no output from the variable.

I found this old bug request where someone had expected a similar output.
http://bugs.modx.com/issues/8468