| Level | Code | Display | Definition | 
 | 1 | alternate  | alternate | 
                        Designates substitute versions for the document in which the link occurs. When used together with the lang attribute, it implies a translated version of the document. When used together with the media attribute, it implies a version designed for a different medium (or media). 
                      | 
 | 1 | appendix  | appendix | 
                        Refers to a document serving as an appendix in a collection of documents. 
                      | 
 | 1 | bookmark  | bookmark | 
                        Refers to a bookmark. A bookmark is a link to a key entry point within an extended document. The title attribute may be used, for example, to label the bookmark. Note that several bookmarks may be defined in each document. 
                      | 
 | 1 | chapter  | chapter | 
                        Refers to a document serving as a chapter in a collection of documents. 
                      | 
 | 1 | contents  | contents | 
                        Refers to a document serving as a table of contents. Some user agents also support the synonym ToC (from "Table of Contents"). 
                      | 
 | 1 | copyright  | copyright | 
                        Refers to a copyright statement for the current document. 
                      | 
 | 1 | glossary  | glossary | 
                        Refers to a document providing a glossary of terms that pertain to the current document. 
                      | 
 | 1 | help  | help | 
                        Refers to a document offering help (more information, links to other sources of information, etc.). 
                      | 
 | 1 | index  | index | 
                        Refers to a document providing an index for the current document. 
                      | 
 | 1 | next  | next | 
                        Refers to the next document in a linear sequence of documents. User agents may choose to preload the "next" document, to reduce the perceived load time. 
                      | 
 | 1 | prev  | prev | 
                        Refers to the previous document in an ordered series of documents. Some user agents also support the synonym "Previous". 
                      | 
 | 1 | section  | section | 
                        Refers to a document serving as a section in a collection of documents. 
                      | 
 | 1 | start  | start | 
                        Refers to the first document in a collection of documents. This link type tells search engines which document is considered by the author to be the starting point of the collection. 
                      | 
 | 1 | stylesheet  | stylesheet | 
                        Refers to an external style sheet. See the section on external style sheets for details. This is used together with the link type "Alternate" for user-selectable alternate style sheets. 
                      | 
 | 1 | subsection  | subsection | 
                        Refers to a document serving as a subsection in a collection of documents. 
                      |