RFC 491 · UNKNOWN · 1973
MON · 15 JUN 2026
What is "Free"?
Overview
RFC 491, “What is "Free"?”, is an Unknown document published in April 1973 by M.A. Padlipsky. The canonical text is published by the RFC Editor.
What “Unknown” means
The standards-track status of this early RFC was never formally classified.
Read this RFC
The canonical text of RFC 491 is hosted at rfc-editor.org. Available in TXT,HTML.
Other RFCs from 1973
- RFC 490 Surrogate RJS for UCLA-CCN
- RFC 492 Response to RFC 467
- RFC 489 Comment on resynchronization of connection status proposal
- RFC 493 GRAPHICS PROTOCOL
- RFC 488 NLS classes at network sites
- RFC 494 Availability of MIX and MIXAL in the Network
- RFC 487 Free file transfer
- RFC 495 Telnet Protocol specifications