Issue variants

Hi folks,  Variants are an active topic of discussion within the GCD right now.  I see that you have a variantCover description field, which handles one of the most common cases.  However, there are a number of "variants" in GCD terminology.  Newsstand vs direct distribution.  Price variants.  Some publishers published versions of issues with ads and without ads.  Etc.
  If you want to handle more types of variants than just covers, I would recommend considering changing "variantCover" to "variantName" or something similar.  Depending on how much detail you want to get into, I can talk about how we're considering putting some more structure around variants, as collectors care a lot about some types (incentive covers) but less about others (newsstand vs direct).
  There is also the question of how to refer to an issue in general, without specifying a particular variant.  We haven't actually sorted that out- it's a topic from the past week or two.
  I'm not trying to get the schema to handle every little thing here, I'm just trying to raise topics that have caused us difficulty.  I'll happily drop any topic deemed out of scope.
thanks,-henry