Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> I find the idea of things being intentionally undocumented quite
> difficult. How is someone coming along supposed to know which things
> are intentionally undocumented and which things are unintentionally
> undocumented?
They should assume the lack of documentation is intentional. Six or
seven years ago your argument might have held some water, but we've
been quite rigorous about requiring externally-visible features to be
documented from the get-go.
regards, tom lane