Please add something like this to the LOGIN/NOLOGIN part:
The `psql` commands `\du` and `\dg` show `Cannot login` for roles with `NOLOGIN` and nothing for roles with `LOGIN`. For other attributes `psql` show their positive forms.
I suspect it is intentional that none (I think...) of the material in the SQL Commands section mentions psql. I can see changing the psql page to note the absence of a positive form presentation for this particular attribute under the descriptions of the \du and \dg meta-commands.