REST metadata - What indicates that a layer has a transparent background?

Discussion created by Gmap4_guy on Jul 25, 2013
I realize the REST API has a &transparent= parameter.  But that is not the subject of my question.

Instead, I would like to know what I can look at in REST metadata to easily tell if a layer was designed with a transparent background.

For WMS metadata I look for opacity=0.

What should I look for in REST metadata?