RFC 5988 - Web Linking https://tools.ietf.org/html/rfc5988#section-5.1
https://www.zhihu.com/question/28557115/answer/48094438
5.5. Examples
For example:
Link: <http://example.com/TheBook/chapter2>; rel="previous";
title="previous chapter"
indicates that "chapter2" is previous to this resource in a logical
navigation path.
Similarly,
Link: </>; rel="http://example.net/foo"
indicates that the root resource ("/") is related to this resource
with the extension relation type "http://example.net/foo".
Nottingham Standards Track [Page 9]
RFC 5988 Web Linking October 2010 The example below shows an instance of the Link header encoding multiple links, and also the use of RFC 2231 encoding to encode both non-ASCII characters and language information. Link: </TheBook/chapter2>; rel="previous"; title*=UTF-8'de'letztes%20Kapitel, </TheBook/chapter4>; rel="next"; title*=UTF-8'de'n%c3%a4chstes%20Kapitel Here, both links have titles encoded in UTF-8, use the German language ("de"), and the second link contains the Unicode code point U+00E4 ("LATIN SMALL LETTER A WITH DIAERESIS"). Note that link-values can convey multiple links between the same target and context IRIs; for example: Link: <http://example.org/>; rel="start http://example.net/relation/other" Here, the link to "http://example.org/" has the registered relation type "start" and the extension relation type "http://example.net/relation/other".