Robert_Charlton - 7:13 am on Mar 16, 2013 (gmt 0)
As discussed in this thread, your choices are schema.org and RDFa....
Ways of marking up a page for a Product
I noted in the discussion that, going forward, schema.org is the microdata format that will be supported by the big three search engines.
In the Google Support article cited [support.google.com...] ...these particular Q&As apply. I believe that the second quote below particularly addresses your concern....
Q: Does schema.org support all the information types already supported for microdata/microformats/RDFa?
A: Yes. Anything that could be done using a previous markup format can be done using schema.org.
Q: My website contains content that isn’t supported by schema.org. Will you add it? How do I mark it up in the meantime?
A: If you publish content of an unsupported type, you have three options:
Do nothing (don’t mark up the content in any way). However, before you decide to do this, check to see if any of the types supported by schema.org—such as reviews, comments, images, or breadcrumbs—are relevant.
Use a less-specific markup type. For example, schema.org has no "Professor" type. However, if you have a directory of professors in your university department, you could use the Person type to mark up the information for every professor in the directory.
If you're feeling ambitious, use the schema.org extension system to define a new type.
See the above pages for more references.