Player-session MUD protocol

MNES

MUD New Environment Standard

Niche use Documented current use

Standardizes MUD-oriented client, version, charset, and capability variables over NEW-ENVIRON.

Protocol overview

First seen: Date not established
Present-day status: Niche use
In use today?: Yes, with documented current use.
Legacy?: No.
Layer: Player-session MUD protocol
Transport: Telnet NEW-ENVIRON option 39
Telnet option: 39
Research validated: 2026-08-29

Current use and fit

Supported by TinTin++ and optionally by Mudlet, but less universal than TTYPE and MTTS.

Implementation essentials

Negotiate NEW-ENVIRON and request only recognized VAR and USERVAR keys.
Escape NEW-ENVIRON control bytes.
Treat reported values as capability hints.

Compatibility and safety notes

Never use environment values for authorization.
Use MNES alongside, not instead of, TTYPE and MTTS.

Original specifications and sources

MUDhalla specification Primary
RFC 1572 NEW-ENVIRON Standard

Where an original site has disappeared, a preservation archive is linked and identified as such. MUDVerse does not claim authorship of the original protocol.