We use the term supplementation for a construction containing an anchor and a supplement, an element related semantically to the anchor, but not integrated into the syntactic structure as a dependent. Supplements are detached prosodically from the anchor, typically having the character of an interpolation or an appendage (an element added loosely at the beginning or end of a clause). Examples are in italic:
This is a companion discussion topic for the original entry at http://grammarerror.com/tags/supplementation