I mentioned my machine tag idea on an earlier thread:
http://groups.google.com/group/activity-streams/browse_thread/thread/...

I wanted to bring it up again because Flickr has a post that describes the
power of machine tags:

http://code.flickr.com/blog/2008/12/15/machine-tag-hierarchies/

They link to another post that I think is useful to consider:

http://code.flickr.com/blog/2008/07/18/wildcard-machine-tag-urls/

What's most interesting here is that if we start publishing activity machine
tags, we could quickly build a Flickr-style API on top of it:

http://www.flickr.com/services/api/flickr.machinetags.getNamespaces.html
http://www.flickr.com/services/api/flickr.machinetags.getPredicates.html
http://www.flickr.com/services/api/flickr.machinetags.getValues.html
http://www.flickr.com/services/api/flickr.machinetags.getPairs.html

And, for an example of how this can manifest itself, check this out:

http://husk.org/code/machine-tag-browser.html

Now imagine being able to consume FriendFeed in an experience like that...!

The crux of this proposal is the identify actors, verbs and objects in ATOM
categories, like so:

    <category term="activity:actor=factoryjoe" scheme="
http://activitystrea.ms/schema/1.0/"/>
    <category term="activity:object-type=photo" scheme="
http://activitystrea.ms/schema/1.0/"/>
    <category term="activity:verb=post" scheme="
http://activitystrea.ms/schema/1.0/"/>

or in RSS, like this:

<media:category scheme="http://activitystrea.ms/schema/1.0/
"> activity:actor=factoryjoe activity:object-type=photo
activity:verb=post </media:category>

Chris

--
Chris Messina
Citizen-Participant &
 Open Technology Advocate-at-Large
factoryjoe.com # diso-project.org
citizenagency.com # vidoop.com
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Hmm, interesting.
I guess the reason why I might push back on that, initially, is that feed
consumers might have their own uses for machine tags (i.e. flickr,
upcoming). Not that the scheme couldn't hint that the category should be
interpreted as a machine tag, but I think there might be something lost from
that approach... not sure.

Perhaps what you're suggesting is exactly how the scheme attribute of
category tags are supposed to be used, in which case I'd like to hear from
the Flickr folks what they think about that.

I can tell you that when I use custom machine tags on Flickr, they show up
in my ATOM feed like this:

<category term="iusethis:app=imageoptim" scheme="
http://www.flickr.com/photos/tags/" />

As for the point about actors, I tend to agree that full URLs would be more
useful. I wonder, though, if we can make some kind of aesthetic
optimization, where, if no base URL is provided for the actor, we could
simply provide a category with an sgnodemapper-derived value?

<category term="factoryjoe" scheme="sgn://flickr.com/?ident" />

Not sure about that though.

Thanks for the feedback! Others?

Chris

On Thu, Dec 18, 2008 at 7:16 PM, NeilFred Picciotto <neilf...@gmail.com>wrote: