Subject: [PATCH] Reserve protocol 3.1 explicitly in pqcomm.h

From: Jacob Champion <[email-masked]>
Date: Tue, 20 Jan 2026 15:04:44 -0800

Hi,

This is a tiny followup to https://postgr.es/c/0664aa4ff8 that
enshrines the unused 3.1 protocol version as PG_PROTOCOL_RSRV31. The
patch comes from [1]; I just wanted to give people the opportunity to
bikeshed the name (or object to the move?) before it becomes part of a
public header.

Thanks,
--Jacob

[1] https://postgr.es/m/CAOYmi%2B%3DPMq5wiKjBuOF2_W6JYRnPFYbgp7P-MRa2ymFo89%3D6BQ%40mail.gmail.com

---

From: Tom Lane <[email-masked]>
Date: Tue, 20 Jan 2026 18:10:49 -0500

> bikeshed the name (or object to the move?) before it becomes part of a

+1 for concept, but I agree the name needs bikeshedding.  "RSRV"
is unreadable, and people might well mentally expand it to
something involving "server", leading to confusion.

How about "PG_PROTOCOL_RESERVED_31" or
"PG_PROTOCOL_UNUSED_31"?

			regards, tom lane

---

From: Jacob Champion <[email-masked]>
Date: Tue, 20 Jan 2026 15:17:37 -0800

> How about "PG_PROTOCOL_RESERVED_31" or

I'd be fine with either; slight preference for "RESERVED" I suppose?

Thanks!
--Jacob

---

From: "Jelte Fennema-Nio" <[email-masked]>
Date: Wed, 21 Jan 2026 08:50:03 +0100

> I'd be fine with either; slight preference for "RESERVED" I suppose?

RESERVED seems clearer to me. And for people interested in why, the
comment above its definition describes it suffiecently.