The filingHistoryList resource states that filing_history_status is an optional field with a single possible value (file_history_available).
Based on that I'd been operating under the assumption that this was essentially a binary yes/no as to whether or not the file history was available. However, this isn't actually the case. There is an enumaration file for multiple possible values in the GitHub repository... it just doesn't mention this anywhere in the documentation.
Documentation issues in general, are a big problem for anyone trying to use this service. As we don't have access to the raw data and we don't have access to the logic the Beta search site uses when it consumes API responses, we're almost entirely relient on the documentation. And if that fails we often have to resort to trial and error, which is somewhat less than ideal in a dataset of this size.
There's been talk about redoing the documentation and bringing it up to date for well over year. Is there any kind of update or timescale with regards to that?