N-Quads backwards compatibility with respect to UTF-8/US-ASCII

The N-Triples specification contains a reference to the previous
content-type (text/plain) being linked to US-ASCII specifically [1].

Could an equivalent section also be added to the N-Quads specification [2]
with reference to the previous specification and the use of text/x-nquads
with US-ASCII [3].

Thanks,

Peter

[1] http://www.w3.org/TR/2013/NOTE-n-triples-20130409/#sec-other-media-types
[2] http://www.w3.org/TR/2013/NOTE-n-quads-20130409/#sec-mediatype
[3] http://sw.deri.org/2008/07/n-quads/#n-quads