IETF RFC 2369 PDF

The mailing list command specification header fields are a set of structured fields to be added to email messages sent by email distribution lists. Each field typically contains a URL (usually mailto [RFC2368]) locating the relevant information or performing the command directly. The three core header fields described in this document are List-Help, List-Subscribe, and List-Unsubscribe.

The three core header fields described in this document are List-Help, List-Subscribe, and List-Unsubscribe. There are three other header fields described here which, although not as widely applicable, will have utility for a sufficient number of mailing lists to justify their formalization here. These are List-Post, List-Owner and List-Archive.

By including these header fields, list servers can make it possible for mail clients to provide automated tools for users to perform list functions. This could take the form of a menu item, push button, or other user interface element. The intent is to simplify the user experience, providing a common interface to the often cryptic and varied mailing list manager commands.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.