The content element <http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html#content-element> says the select attribute “defines the matching criteria for distributing child nodes of the host element. Each token must be a valid selector fragment.”

Selector fragments <http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html#dfn-selector-fragment> define the meaning of “matching” for a single selector fragment.

However nowhere is it defined what ”matching” means for multiple selector fragments. Any of the fragments? All of the fragments? (What if there are zero fragments?)