Follow up on singularity changeset

Seems like we missed a couple of properties which should have been changed
to their singular form. Most of the properties at the bottom of the unchanged
properties of the Singularity
proposal<http://www.w3.org/wiki/WebSchemas/Singularity#Unchanged_.2A-s_properties>
should
remain plural, but 'ingredients' from Recipe
<http://schema.org/Recipe>ought to be singular since 1) its definition
is "An ingredient used in the
recipe." and 2) the example shows a list of multiple instances of
ingredients. Finally 'ingredient' (singular) is consistent with the
property defined in the Google documentation for Rich snippets -
Recipes<http://support.google.com/webmasters/bin/answer.py?hl=en&answer=173379>
and
used in microformats, microdata and RDFa. (I know this is not schema.org,
but it will make the migration to schema.org markup easier and less error
prone).

'offers' is another one that I think should be singular. It is used in
CreativeWork <http://schema.org/CreativeWork>,
MediaObject<http://schema.org/MediaObject>
, Event <http://schema.org/Event>, and Product <http://schema.org/Product>.
Maybe it was meant to be the third person, but still that does not make
sense: "Event has an Offer" sounds right, but "Event offers an Offer" does
not sound right.

Dan, I'm happy to put this in the wiki, can I update the existing proposal
even though it's marked published, or should this go into a new page?

Steph.