Foundation or terminal standard

TTYPE

Telnet Terminal Type

Widely used Documented current use

Allows a server to request one or more terminal or client identity strings; MTTS extends the reply sequence.

Protocol overview

First seen: 1989
Present-day status: Widely used
In use today?: Yes, with documented current use.
Legacy?: No.
Layer: Foundation or terminal standard
Transport: Telnet option 24
Telnet option: 24
Research validated: 2026-08-29

Current use and fit

Broadly implemented and the normal foundation for MTTS capability discovery.

Implementation essentials

Send DO TTYPE, then request values with TTYPE SEND after WILL.
Allow values to cycle as RFC 1091 permits.
Stop repeated probing when values repeat.

Compatibility and safety notes

Do not assume a fixed number of replies.
Client names are self-asserted.

Original specifications and sources

RFC 1091 Terminal-Type Option Standard
MUDhalla MTTS specification Primary

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