add field to indicate if a dataset is "Retired"

[rebeccawilliams]

See @bsweger's comments:

Thanks for opening this! I was thinking specifically about data that's definitively, well-and-truly retired. Which seems hard to know for sure unless an agency or subject matter expert weighs in.

For example, the Census Bureau dropped CFFR and Federal Aid to States in the FY 2012 budget, so the latest available data is FY 2010.

In contrast, some agencies publish data on an irregular schedule (IRS zip code income taxes) or publish survey data that isn't updated annually.

Above exceptions aside, it could be useful to track "suspiciously old-looking" data, but that risks casting aspersions on information that's not actually out of date. Ideally, agencies would report past submissions as retired.

Many data.gov improvement ideas (like this one) would involve submitters considering their inventory as a holistic entity and not as individual datasets, which seems like a more involved process issue.

See also:

• https://project-open-data.cio.gov/v1.1/schema/#isPartOf
• https://project-open-data.cio.gov/v1.1/schema/#temporal

Questions: Should this be for Collections only? Does DCAT or ISO 8601 address this?