Definition of Tag
Definition Last Updated 2015-10-28 14:39
A tag is a kind of characteristic, i.e. something that can be said about1Formally, predicated of the content of a particular region at a particular time; tags differ from observables (the only other kind of characteristic) in that, whereas observables are intrinsic characteristics such as length or mass, tags are independent, extrinsic characteristics such as identity that are typically attributed to an entity once it has been identified,.
Being about something, a tag and its value constitute metadata.
Relationships are defined by attributing tags.
Article Last Updated 2015-10-28 14:39
Since tag data is external to a thing, the information that it contains about that thing can only be examined if, given the thing itself, there is some way to locate the tag data, i.e. there is a relationship between the thing and the entity that encodes its tag data.
However, since relationships are implicitly defined by tags attributed to regions, thereby making them into entities, and tags are by definition extrinsic to the things being related, the relationship between a thing and its tags cannot be found in the thing itself.
This is a problem; how do we know what we know about something when what we know about something depends on knowing that the something we know is about some particular thing that can only be identified by something that it is not intrinsically tied to?
It is a problem, but not one we should dwell on here, though the answer may lie in the repetition of the identification process, i.e. repeated application of descriptions, leading to repeated re-identification which then allows the relevant relationship to be re-established.
Notes [ + ]
|1.||⬆||Formally, predicated of|