[foaf-dev] foaf:logo definition

Richard Cyganiak richard at cyganiak.de
Sun Aug 15 21:50:59 CEST 2010

On 15 Aug 2010, at 00:00, Dan Brickley wrote:
> Can you give an example of public online RDF that uses foaf:logo in a
> way that's screwed up by the IFP claim?

Here are five distinct things with same foaf:logo:

Here are two distinct things with the same foaf:logo (well, visually  
-- they have different URLs):
foaf:logo statements here:

I can't find a foaf:logo assertion, but the organisation I work for  
(DERI Galway) shared a logo with the now defunct DERI Innsbruck.

I often buy overpriced coffee in a coffee shop that shares a logo with  
a few thousand other coffee shops.

I'm wearing a T-Shirt that by your logic would have to be smushed with  
the shoes of another person sitting in this room.

> Would clarification in the prose help? eg. "logo - A logo representing
> some *specific* thing."

How about: “logo - A logo specifically representing this single thing.  
A logo is a graphic mark or emblem that is used by an organisation or  
individual to promote instant public recognition of some thing. If two  
things have the same foaf:logo, they are considered to be actually the  
same thing. Therefore, do not use foaf:logo with logos that represent  
multiple things (such as a company and its products or its store  
locations), have been owned by multiple legal entities throughout  
their existence, have been appropriated by other organisations, are  
used for different versions of the same thing, or might otherwise bei  
interpreted as representing a number of distinct things.”

> the essence is that a single entity is promoting the image as its  
> symbol;

> as soon as multiple related entities are doing so, without consensus
> on what it's the logo *for*, then it falls into a vaguer category?

Even if only a single entity promotes the use of a logo, this does not  
imply any consensus on what it uniquely identifies (a company, a  
brand, a branch, a product?).

If you venture outside of the area of trademarks, there is no  
mechanism in place that ensures uniqueness of logos (unlike homepages  
and email addresses, where a technical mechanism is in place). Sure  
it's a bad idea to have the same logo as something else, but people do  
stupid things all the time.

So the IFP claim--that two different things can never have the same  
logo--is either false and needs to be removed, or requires a very  
different and much narrower prose definition of what it means to have  
a foaf:logo. With the narrower definition, the property would be no  
longer very useful IMO, and doesn't feel like the kind of thing that  
should be in FOAF. Hence, my vote for reverting this change.


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