> They're avoiding specifying a format until they're sure that it's nailed down, does what they need, doesn't have some unforseen problem that could only be found through widespread testing, etc.
This is understandable, even appreciated. Having multiple minor versions of varying usefulness indefinitely supported just because they existed for a commit or two during the inital format designs would be crazy to expect.
> Once it's a stable feature, expect the format to be documented.
FTA:
> At this point we have no intention to standardize the format . We might document the on-disk format eventually
This is not a strong a guarantee as I'd like for this and certainly not something that would range a high level of expectancy from me. Before it becomes default in a major distribution, I'd like to see a format specification.