The current docs can be read as using DISTINCT in an aggregate
(count(distinct col)) and ORDER BY (array_agg(col ORDER BY col)) are
both extensions to the standard.
The actual truth is that our extension to the standard is to allow both
at the same time.
Attached is a trivial patch to make that more clear. I don't know if
pgindent works on the docs so I made this so as to show what is
changing. I can submit a properly formatted patch, or let the eventual
committer make that change if necessary.
--
Vik Fearing