What means "<ELmarker>{empty from}"?

[hbender]

The seam-gen (2.2) generates conditional EL expressions like "#{empty from ? ...} ". I cannot find any documentation what "from" stands for. Where can I find documentation about such placeholders?
Thanks
Heri

[rhoppe]

Late but ...

from is a parameter passed to the page (see xxx.page.xml)

Hope this helps.