Constant async_coap::link_format::LINK_ATTR_REL

pub const LINK_ATTR_REL: &'static str

Relation Type.

From IETF-RFC8288, Section 3.3:

The relation type of a link conveyed in the Link header field is conveyed in the "rel" parameter's value. The rel parameter MUST be present but MUST NOT appear more than once in a given link-value; occurrences after the first MUST be ignored by parsers.

The rel parameter can, however, contain multiple link relation types. When this occurs, it establishes multiple links that share the same context, target, and target attributes.

The ABNF for the rel parameter values is:

    relation-type *( 1*SP relation-type )

where:

    relation-type  = reg-rel-type / ext-rel-type
    reg-rel-type   = LOALPHA *( LOALPHA / DIGIT / "." / "-" )
    ext-rel-type   = URI ; Section 3 of [RFC3986]

Note that extension relation types are REQUIRED to be absolute URIs in Link header fields and MUST be quoted when they contain characters not allowed in tokens, such as a semicolon (";") or comma (",") (as these characters are used as delimiters in the header field itself).

Optional in IETF-RFC6690 link format resources.