Triple tags on Twitter

Triple tags (known as Machine Tags on Flickr) are a way of tagging web content with tags having three parts: a namespace, a predicate and a value. This means that we can differentiate between content about a (tagged taxonomy:vernacular=beagle) and (tagged maritime:vessel=beagle). Of course, that relies on everyone using the same tagging schema (my two examples could also be tagged with, say, pet:dog=beagle and history:ship=beagle). Fortunately, communities of web authors are agreeing on such schema.

One schema that is widely used is for geo- (or location-) tagging, where posts such as my picture of a Kingfisher on Flickr are tagged with (in that case):

  • geo:lat=-1.56403
  • geo:lon=53.60913

In other words, the coordinates of the place where I took the picture (pages using that schema are also often tagged with ““).

Kingfisher at Bretton Lakes, South Yorkshire

It is then possible for Flickr to display that picture overlaid on a map of the location.

The Flickr page is also tagged:


which gives the scientific name (binomial or binominal) of the Common Kingfisher, Alcedo atthis, including the Genus, Alcedo.

Another form of tagging, using hash tags, is used by the social media text-messaging service Twitter. Tags in twitter are prefixed with a hash symbol (#), hence the name. A “hash-tagged” message might look like:

I live in #England

Hash tags are parsed by three sites that I know of (there may be others — if so, please let me know): Hashtags (e.g. ), Summize (Summize for “#blog”) and Twemes ().

All well and good.

It occurred to me recently that it should be possible to use Triple tags in Twitter messages, so I posted these “tweets” as they’re called (I find that rather, er, twee):

#tagged post about #Kingfisher #taxonomy
( #taxonomy:genus=Alcedo,
#taxonomy:binomial=Alcedo_atthis )



Is anyone is parsing #geotagged posts like this: #geo:lat=52.478342 #geo:lon=-1.895389 ( #birminghamuk #rotunda #geo #geotag #tripletag)


(line breaks have been inserted to improve readability)

Disappointingly, none of the three hash tag parsers above managed to understand these. They all see “#geo:lat=52.478342” as just “#geo” and “#taxonomy:binomial=Alcedo_atthis” as just “#taxonomy”.

Worse still, Hashtags wrongly displays my two posts without the second two-thirds of the tag content, as:

#tagged post about #Kingfisher #taxonomy ( #taxonomy #taxonomy )



Also wonder if anyone is parsing #geotagged posts like this: #geo #geo ( #birminghamuk #rotunda #geo #geotag)


See also:

Wouldn’t it be great if services which parse hash tags in Twitter messages also recognised “hash-triple-tags”?

[Update: Summize was bought by Twitter and is now absorbed by them as Twitter’s own search.]

[Update: now parses the triple tags as, for example, just “#taxonomy”]

[Update: David Carrington of Dabr tells me that some of these triple tags are too long for Twitter’s search API. I’ll try to find out what the limit is, and raise the matter with Twitter’s support people]

[Update: There is now a tool to automatically generate tags for Flickr images of living things; iNaturalist tagger.]


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8 Responses to “Triple tags on Twitter”

  1. jon Says:

    What doyou think about creating a geotag specific for twitter providing something similar to hastags.og but focused online on geotags? Looking forward to your two cents..

  2. pigsonthewing Says:

    @jon – How would you envisage that working, and how would it differ from the “triple tag” format described above? We shouldn’t invent new ways of doing things, where existing methods can be reused.

  3. pigsonthewing Says:

    Twemes defend this on the grounds that triple tags are (were!) not covered in the hashtag “spec”, and claim a clash with colons as punctuation in casual conversation. The latter is bogus, as colons in conversation are generally followed by a space: as in this sentence. Also, plain-text sentences using a colon, followed by an equal sign, and preceded by a hash, and without spaces, #are:extremely=unlikely.

    I’ve added this as an issue, to the “spec”, but it’s not really a spec, just a wiki page at PBWiki, describing how hastags might be used.

  4. Remmrit Bookmarking Says:

    Taxonomy Bookmarks… user has just tagged your post as taxonomy!…

  5. Navarr Says:

    Upon finding this in the Twitter fan wiki and the addition of the third and second layer hashtags to the protocol (which i found out about just now), I’ve coded support for second and third layer hashtags into operaTwitter (name is link). I hope that other developers will soon follow suit.

  6. Andy Says:

    The BBC have used triple tagging in twitter for their Bangladesh River Journey:, using the triple tags to pull their tweets into Google maps.

    Not sure how they’re pulling their flickr photos in though.

  7. Triple-tag references to Twitter posts « Mabblog Says:

    […] By pigsonthewing Further to my post about a protocol for Twitter posts, you can also triple-tag blog posts, Flickr images and similar web utterances, which refer to a specific twitter post (or […]

  8. pigsonthewing Says:

    Further discussion at

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