{"id":12,"date":"2004-08-25T15:31:10","date_gmt":"2004-08-25T15:31:10","guid":{"rendered":"http:\/\/lachy.id.au\/log\/2004\/08\/link-relationships"},"modified":"2006-04-30T23:54:13","modified_gmt":"2006-04-30T23:54:13","slug":"link-relationships","status":"publish","type":"post","link":"https:\/\/lachy.id.au\/log\/2004\/08\/link-relationships","title":{"rendered":"Link Relationships"},"content":{"rendered":"

This is in repsonse to Ian Hickson’s<\/cite><\/a> recent Strange\r\n\t\t\tspam to W3C lists<\/cite><\/a> article. In it he writes:<\/p>\r\n

\r\n\t

I’m thinking that HTML should have an element that basically says “content\r\n\t\twithin this section may contain links from external sources; just because they\r\n\t\tare here does not mean we are endorsing them” which Google could then use to\r\n\t\tblock Google rank whoring. I know a bunch of people being affected by Web log\r\n\t\tspam would jump at that chance to use this element if it was put into a spec.<\/p>\r\n<\/blockquote>\r\n

This is my idea for a solution to his request. It involves defining a profile\r\n\tof values for the rev<\/code><\/a> and rel<\/code><\/a> attributes\r\n\tin (X)HTML<\/abbr>. All link\r\n\trelationships described here provide additional semantic information that can\r\n\tpotentially be used by search engines to increase the accuracy of page ranking\r\n\talgorithims; and other user agents to enhance accessibility and usability of\r\n\ta document. This further enhances, and makes use of the democratic nature of\r\n\tthe web which was the foundation of the google’s page rank algorithm, by giving\r\n\tauthors more control over the pages their links vote<\/em> for.<\/p>\r\n\r\n

Update:<\/strong>\r\n In response to a discussion between myself and Peter Janes<\/a> in his blog entry<\/a>, I realized that I should clarify that the intention of this is to create an XMDP<\/abbr><\/a>, similar to XFN<\/abbr><\/a>.<\/p><\/ins>\r\n\r\n

Currently, the only way to vote for a page is to link to it. Essentially,\r\n\teach link counts as one vote. It is then weighted according to several different\r\n\talgorithms ranging from the page rank of the linking document, to their similarity\r\n\tin content, and many other things. There is currently no way for an author to\r\n\tsay that the page being linked to is a result of user\r\n\tfeedback<\/a>, to specify its quality<\/a>, accuracy<\/a> and\/or accessibility<\/a>;\r\n\tnor to provide a rating<\/a>, or say whether or not it is an endorsement<\/a> or\r\n\tadvertisment of any kind.<\/p>\r\n

For this reason, comment spammers with the intent of increasing the number\r\n\tof links, and thus page rank has become somewhat of a problem. This occurs mostly\r\n\ton blogs and as pointed out by Ian, also in archived mailing lists<\/a>. In order\r\n\tto combat this problem, there exists a need for authors to be able to specify\r\n\twhich links from their pages should count towards page rank, and which should\r\n\tnot.. Additionally, there should be a way to provide additional semantic information\r\n\tthat could be used by any user agent in a variety of ways to filter and access\r\n\tresources based on user settings. For example, a user agent may harvest all\r\n\tthe pingback and trackback URIs<\/abbr> in\r\n\ta document, or those that the author considers to be high quality and list them\r\n\tto the user for quick access. These relationships have been broken into the\r\n\tcategories I mentioned earlier: user feedback<\/a>, quality<\/a>, accuracy<\/a>, accessibility<\/a>, rating<\/a> and endorsement<\/a>.<\/p>\r\n

User Feedback<\/h5>\r\n

These relationships indicate a link to a resource owned by a reader<\/strong> of\r\n\tthe document, that has provided feedback to the author<\/strong> in the\r\n\tform of a pingback<\/code><\/a>, trackback<\/code><\/a> or comment<\/a><\/code>.\r\n\tThese relationships are mutually exclusive and, therefore, should not be used\r\n\ton the same link.<\/p>\r\n

\r\n\t
pingback<\/code><\/dt>\r\n\t
\r\n\t\t

This relationship has already been defined in in the Pingback\r\n\t\t\t\t1.0 specification<\/a> but is included here to further describe its potential\r\n\t\t\t\tuse as a means for search engines to determine page rank information.<\/p>\r\n\t\t

When used with the rel<\/code> attribute, this relationship has been\r\n\t\t\tdefined to indicate the pingback URI of a resourse. However, when used with\r\n\t\t\ta rev<\/code> attribute, this should indicate the reverse situation.\r\n\t\t\tie. that the resource designated by the link URI<\/abbr> has\r\n\t\t\tpinged the document.<\/p>\r\n\t<\/dd>\r\n\t

trackback<\/code><\/dt>\r\n\t
\r\n\t\t

This is similar to pingback, and may be considered to be a synonym for pingback.\r\n\t\t\tThe difference is only in the implementation of the feedback mechanisms. Both\r\n\t\t\tare included because it may be useful for authors to have a semantic difference\r\n\t\t\tbetween the two for whatever reason.<\/p>\r\n\t<\/dd>\r\n\t

comment<\/code><\/dt>\r\n\t
\r\n\t\t

This can be used to indicate, using the rel<\/code> attribute, that\r\n\t\t\tthe resource indicated by the URI<\/abbr> is\r\n\t\t\ta document<\/del> owned, or has just been referenced<\/ins> by a person who has left a pingback<\/code>, trackback<\/code> or comment<\/code> provided\r\n\t\t\tvia a form. The resource indicated by a link with this relationship should\r\n\t\t\tnot be considered directly related to the document, and thus the presence\r\n\t\t\tof the link alone should not increase the page rank of the linked resource.\r\n\t\t\tHowever, search engines may further analyse the content of the resource to\r\n\t\t\tdetermine if it is infact related, and if so, increase the page rank accordingly.\r\n\t\t\tIn cases where the content is completely unrelated, the page rank should\r\n\t\t\tnot<\/strong> be reduced. This is because people can, and do leave legitimate\r\n\t\t\tcomments despite having vastly different content on their site.<\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n

Examples:<\/h6>\r\n

In this example, Eric Meyer has been marked as the person who commented, and\r\n\this article has been marked as the resource that pinged the document. <\/p>\r\n

1. <a href="http:\/\/www.meyerweb.com\/eric\/thoughts\/2004\/08\/24\/more-markup\/"\r\n      rev="pingback">Pingback<\/a> by\r\n   <a href="http:\/\/www.meyerweb.com\/"\r\n      rel="comment">Eric Meyer<\/a><\/code><\/pre>\r\n
Quality<\/h5>\r\n
These relationships indicate the authors opinion about the quality of the\r\n\tresource. These should be considered to be either a positive or negative vote\r\n\tfrom the author. A resource with many links that mostly indicate poor<\/code><\/a>, or awful<\/code><\/a> quality\r\n\tshould not rank as high as a resource that may have fewer links to it, but that\r\n\tmostly indicate good<\/code><\/a>, or excellent<\/code><\/a> quality.\r\n\tThese relationships are mutually exclusive, and should not appear within the\r\n\tsame attribute. A rating appearing in the rel<\/code> attribute indicates\r\n\tthat the author of the document is rating the linked resource; whereas a rating\r\n\tin the rev<\/code> attribute indicates that the author of the linked resource\r\n\thas rated the document containing the link. Thus, it is allowable to have two\r\n\tquality attributes on the same link, each on the different attribute.<\/p>\r\n
\r\n\t
excellent<\/code><\/dt>\r\n\t
The author of the document believes the resource to be of excellent quality.\r\n\t\tThis is the highest quality, and should be given the highest weighting compared\r\n\t\twith the other quality relationships. A resource that has been given this relationship\r\n\t\tshould be considered as recommendation for others to read the linked resource,\r\n\t\tand thus should be counted as a positive vote from the author.<\/dd>\r\n\t
good<\/code><\/dt>\r\n\t
\r\n\t\t
The author beleives the resource is of reasonably good quality, that may\r\n\t\t\tbe interesting for many people. This should be counted as a positive vote,\r\n\t\t\tbut not rated as highly as excellent<\/code><\/a>.<\/p>\r\n\t<\/dd>\r\n\t
average<\/code><\/dt>\r\n\t
\r\n\t\t
This value indicates that the author does not consider the resource to be\r\n\t\t\tgood or bad. Although this should be counted as a postive vote, page rank\r\n\t\t\tfor this resource should be determined mostly in the normal way. The difference\r\n\t\t\tbetween using this value, and no value at all is that the author has explicitly\r\n\t\t\tdefined the document to be of average quality, whereas it is undefined otherwise\r\n\t\t\tand may infact be of any quality. This value may be of more use to other user\r\n\t\t\tagents, in the ways mentioned earlier; or for the purpose of styling with CSS<\/abbr>.<\/p>\r\n\t<\/dd>\r\n\t
poor<\/code><\/dt>\r\n\t
\r\n\t\t
The author does not consider the resource to be useful, and does not recommend\r\n\t\t\tit to many people. This should be counted as a negative vote, but not weighted\r\n\t\t\tas heavily as awful<\/code><\/a>. <\/p>\r\n\t<\/dd>\r\n\t
awful<\/code><\/dt>\r\n\t
\r\n\t\t
The author believes that this resouces is not good at all, and should be\r\n\t\t\tgiven the lowest page rank weighting. The author considers the resourse to\r\n\t\t\tcontain very poor or offensive content that is not worth reading by anyone.<\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n
Examples:<\/h6>\r\n
In example 1, the author has declared the content of the CSS<\/abbr> Zen\r\n\t\tGarden<\/a> to be excellent, and thus voted positively for it. In example 2,\r\n\t\tEric Meyer has pinged the document, declaring it to have good content. Additionally,\r\n\t\tthe author of the document has specifed that the content of the Eric Meyer’s\r\n\t\tarticle to be average (no offense Eric, this is just an example)<\/em> but\r\n\t\tconsiders the overall content of Eric Meyer’s site to be excellent.<\/p>\r\n
1: <p>Dave Shea is the creator of the\r\n      <a href="http:\/\/www.csszengarden.com\/"\r\n         rel="excellent">CSS Zen Garden<\/a><\/p>\r\n\r\n2: <a href="http:\/\/www.meyerweb.com\/eric\/thoughts\/2004\/08\/24\/more-markup\/"\r\n      rev="pingback good" rel="average">Pingback<\/a> by\r\n   <a href="http:\/\/www.meyerweb.com\/"\r\n      rel="excellent comment">Eric Meyer<\/a><\/code><\/pre>\r\n
Accessibility<\/h5>\r\n
These values indicate the accessibility rating of a document according to\r\n\tvarious accessibility initiatives. These do not indicate that the quality of\r\n\tthe document is good or bad in any way; just that the document may or may not\r\n\tbe easily read and accessed by users of assistive technologies, or infact a\r\n\tsearch engine.<\/p>\r\n
\r\n\t
wcag-A<\/code>, wcag-AA<\/code> and wcag-AAA<\/code><\/dt>\r\n\t
\r\n\t\t
These indicate that the linked resource conforms to the W3C<\/abbr><\/a>‘s WAI<\/abbr><\/a>–WCAG<\/abbr><\/a>: Level\r\n\t\t\t\tA<\/a>, Double-A<\/a> or Triple-A<\/a> accessibility\r\n\t\t\t\trequirements, depending on the level indicated by the value. These may not\r\n\t\t\t\tbe used togethether in the same attribute, but may be used with section-508<\/code><\/a>.\r\n\t\t\t\tThese attributes should count toward increasing the page rank of the resource.<\/p>\r\n\t<\/dd>\r\n\t
section-508<\/code><\/dt>\r\n\t
\r\n\t\t
This indicates that the resource conforms to the Section\r\n\t\t\t\t508<\/a> accessibility guidelines. This should count towards increasing the\r\n\t\t\t\tpage rank of the resource. This is of equal importance to the WAI<\/abbr>–WCAG<\/abbr> values<\/a> <\/p>\r\n\t<\/dd>\r\n\t
non-conformant<\/code><\/dt>\r\n\t
\r\n\t\t
This indicates that the resources does not conform to all the requirements\r\n\t\t\tof any acessibility guideline specification, however the resource may still\r\n\t\t\tbe somewhat accessible to users of assistive technologies. These resources\r\n\t\t\tshould not be given a significantly lowered page rank weighting, but should\r\n\t\t\trate lower than a resource of equivalent, or similar cotent, and of equal\r\n\t\t\tquality, that conforms to section-508<\/code><\/a>, wcag-A<\/code><\/a> or\r\n\t\t\thigher guideline.<\/p>\r\n\t<\/dd>\r\n\t
inaccessible<\/code><\/dt>\r\n\t
\r\n\t\t
The author believes that this resouces is not easily accessible to all users,\r\n\t\t\tand may depend on the use of proprietary technoliges and\/or has plugins without\r\n\t\t\tgood alternate content, or is, in any other way, completely inaccessible to\r\n\t\t\tmany users. These documents should be given a lowered page rank weighting,\r\n\t\t\thowever it should be noted that any resource marked with this value is likely\r\n\t\t\tto be inaccessible to a search engine, and thus will not recieve a high page\r\n\t\t\trank anyway.<\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n
Examples:<\/h6>\r\n
Example 1 has extended the CSS Zen Garden link by further declaring that the\r\n\tcontent is conformant to both WAI<\/abbr><\/a>–WCAG<\/abbr><\/a>, Level\r\n\tTriple-A<\/a> and Section\r\n\t508<\/a> guidelines<\/p>\r\n
1: <p>Dave Shea is the creator of the\r\n      <a href="http:\/\/www.csszengarden.com\/"\r\n         rel="excellent wcag-AAA section-508">CSS Zen Garden<\/a><\/p>\r\n\r\n2: <p>The world's most popular search engine is\r\n      <a href="http:\/\/www.google.com\/"\r\n         rel="non-conformant">Google<\/a><\/p><\/code><\/pre>\r\n
Accuracy<\/h5>\r\n
These values indicate how accurate the author of the document believes the\r\n\tcontent of the resource to be. The more accurate votes received by the resource,\r\n\tthe higher the page rank should be. These values will be most useful for linking\r\n\tto news and information sites, but can apply to any other resource that an author\r\n\twishes.<\/p>\r\n
\r\n\t
accurate<\/code><\/dt>\r\n\t
\r\n\t\t
This is the highets level of accuracy. The author believes that the information\r\n\t\t\tcontained within this resource is very accurate<\/p>\r\n\t<\/dd>\r\n\t
believable<\/code><\/dt>\r\n\t
\r\n\t\t
The author believes that the content contained within the resource is accurate,\r\n\t\t\tbut cannot verify that; or that the resource is mostly accurate but contains\r\n\t\t\tsome information known to be inaccurate.<\/p>\r\n\t<\/dd>\r\n\t
unsure<\/code><\/dt>\r\n\t
\r\n\t\t
The author cannot verify, or dispute the accuracy of the content within\r\n\t\t\tthe resource. There is no evidence either way, and readers should be weary\r\n\t\t\tof any facts and claims made.<\/p>\r\n\t<\/dd>\r\n\t
unbelievable<\/code><\/dt>\r\n\t
\r\n\t\t
The content of the resource makes claims or states facts that are unlikely\r\n\t\t\tto be true, or contains several claims that are known to be incorrect. <\/p>\r\n\t<\/dd>\r\n\t
inaccurate<\/code><\/dt>\r\n\t
\r\n\t\t
The resource contains a large portion of information that is known by the\r\n\t\t\tauthor, to be incorrect.<\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n
Example:<\/h6>\r\n
In example, the author is cheering for is country, and declaring that the\r\n\tarticle about Grant Hackett winning the 1500m swimming final to be both accurate,\r\n\tand excellent news. In example 2, the author has declared that the Microsft’s\r\n\tarticle about conformance to standards is unbelievable and that the resource\r\n\tis non-conformant to accessibility requirements.<\/p>\r\n
1. <p><a href="http:\/\/www.olympics.com\/swimming\/news\/hackett-wins"\r\n         rel="accurate excellent">Grant Hackett wins 1500m Final<\/a> (Go Aussies!)<\/p>\r\n2. <p><a href="http:\/\/www.microsoft.com\/conformance\/"\r\n         rel="unbelievable non-conformant">Microsoft will Conform to Standards Soon<\/a><\/p><\/code><\/pre>\r\n
Rating<\/h5>\r\n
These values indicate the recommended audience for a resource. These could\r\n\tpotentially be used by user agents to help enforce parental restrictions. For\r\n\texample, a user agent could prevent a child from accessing, or provide a warning\r\n\tto users about content that has been labled as restriced, mature-adult, etc.\r\n\tdepending on the user agent’s or other parental control software settings.<\/p>\r\n
\r\n\t
restricted<\/code><\/dt>\r\n\t
\r\n\t\t
The indicates that the resource contains illicit, extremely offensive, or\r\n\t\t\texcessively pornographic content that is not suitable for most users. Search\r\n\t\t\tengines and user agents should not give access to resources of this nature\r\n\t\t\tunless the user fully accepts the responsibility, and explicitly agrees to\r\n\t\t\tview such content.<\/p>\r\n\t<\/dd>\r\n\t
mature-adult<\/code><\/dt>\r\n\t
\r\n\t\t
This indicates that the resource contains material that could be considered\r\n\t\t\toffensive, or inappropriate for many users. Caution should be taken by a user\r\n\t\t\tbefore visiting the resource, and user agents and or search engines may filter\r\n\t\t\tcontent of this kind based on user settings. <\/p>\r\n\t<\/dd>\r\n\t
mature<\/code><\/dt>\r\n\t
\r\n\t\t
The content of this resourse is recommended for mature audiences. User agents\r\n\t\t\tmay or may not allow access to this content depending on the user’s settings.\r\n\t\t\tPage rank should not be affected, as a normal adult would consider this content\r\n\t\t\tacceptable, though would perhaps restrict access to minors.<\/p>\r\n\t<\/dd>\r\n\t
parental-guidance<\/code><\/dt>\r\n\t
\r\n\t\t
For most users, this content will be acceptable. Parental guidance may be\r\n\t\t\tsought, depending on the user agents settings.<\/p>\r\n\t<\/dd>\r\n\t
general<\/code><\/dt>\r\n\t
\r\n\t\t
The content is acceptable for the widest audience. There is no reason to\r\n\t\t\trestrict access to these resources, as they are considered appropriate for\r\n\t\t\tany person. However, a user agent should still allow this contnet to be restricted\r\n\t\t\tby the user for any reason.<\/p>\r\n\t<\/dd>\r\n\t
children<\/code><\/dt>\r\n\t
\r\n\t\t
The content is most suited to, and targeted at children.<\/p>\r\n\t<\/dd>\r\n\t
password<\/code><\/dt>\r\n\t
\r\n\t\t
The resource indicated requires a password to access the full content. This\r\n\t\t\tindicates that registration may be available, or that some content is available\r\n\t\t\tany user, possibly depending on other restrictions in place.<\/p>\r\n\t<\/dd>\r\n\t
member-only<\/code><\/dt>\r\n\t
\r\n\t\t
The resource indicated only allows access to members. No content is available\r\n\t\t\tto non-members, and membership registration may be restricted. <\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n
Example:<\/h6>\r\n
In this example, the member archives have been declared to be accessible to\r\n\tmembers only and also Level Triple-A conformant.<\/p>\r\n
1. <p><a href="http:\/\/lists.w3.org\/Archives\/Member\/"\r\n         rel="member-only wcag-AAA">Member Archives<\/a><\/p><\/code><\/pre>\r\n
Endorsement<\/h5>\r\n
\r\n\t
advert<\/code> or advertisement<\/code><\/dt>\r\n\t
\r\n\t\t
The resource is being linked to because of an agreement between parties\r\n\t\t\tto advertise the resource within the document.<\/p>\r\n\t<\/dd>\r\n\t
endorsed<\/code><\/dt>\r\n\t
\r\n\t\t
The resource indicated carries with it, an endorsement that indicates that\r\n\t\t\tthe author approves of, and recomends the resource.<\/p>\r\n\t<\/dd>\r\n\t
unendorsed<\/code><\/dt>\r\n\t
\r\n\t\t
The resource is not, in anyway endorsed or to be considered approved by\r\n\t\t\tthe author and may be there as a result of an advertising agreement, but does\r\n\t\t\tnot provide any other guarentee about or recommendation for the resource.<\/p>\r\n
Update:<\/strong>  This value may also be used to indicate that a link is from a third party that is not endorsed by the document author.  For example, links posted in an e-mail to, and archived in a mailing list can be marked with this to prevent the page rank of the mailing list, which is likely to be quite high, from increasing the page rank of the resource.  This should help to the never ending flow of spam often distributed to mailing lists, as Ian Hixon mentioned in his article.  This value may be used instead of, or in conjunction with comment<\/code><\/a> for links that have been included within the body text of a comment.  comment<\/code><\/a> should still be used for links to the authors home page, as demonstrated in the example for comment<\/code><\/a>.<\/p>\r\n\t<\/dd>\r\n<\/dl>\r\n
Example:<\/h6>\r\n
In this example, the author has indicated that the link is an advertisment,\r\n\thowever the author also endorses the resource because it may be useful and have\r\n\tgood content and\/or products.<\/p>\r\n
1. <p><a href="http:\/\/www.example.com\/"\r\n         rel="advertisment endorsed good">FooBar<\/a><\/p><\/code><\/pre>\r\n\r\n
That’s about all I can think of now, and I would really appreciate any comment and feedback from anyone.<\/p>","protected":false},"excerpt":{"rendered":"This is in repsonse to Ian Hickson’s recent Strange spam to W3C lists article. In it he writes: I’m thinking that HTML should have an element that basically says “content within this section may contain links from external sources; just because they are here does not mean we are endorsing them” which Google could then … Continue reading Link Relationships<\/span> →<\/span><\/a>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[],"_links":{"self":[{"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/posts\/12"}],"collection":[{"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/comments?post=12"}],"version-history":[{"count":0,"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/posts\/12\/revisions"}],"wp:attachment":[{"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/media?parent=12"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/categories?post=12"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lachy.id.au\/log\/wp-json\/wp\/v2\/tags?post=12"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}