Cross-version Compatibility of postgres_fdw

Hi,

The documentation states that postgres_fdw can be used with remote servers
as far back as PostgreSQL 8.3.
https://www.postgresql.org/docs/devel/postgres-fdw.html#POSTGRES-FDW-CROSS-VERSION-COMPATIBILITY

However, when using PostgreSQL 9.4 or earlier as a remote server,
INSERT ON CONFLICT on a foreign table fails because this feature
is only supported in v9.5 and later. Should we add a note to
the documentation to clarify this limitation?

For example:
"Another limitation is that when executing INSERT statements with
an ON CONFLICT DO NOTHING clause on a foreign table, the remote server
must be running PostgreSQL 9.5 or later, as earlier versions do not
support this feature."

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION