A label is a `kind 1985` note that is used to label other entities. This supports a number of use cases:
- Distributed moderation and content recommendations
- Reviews and ratings
- Definition of edges in a graph structure
This NIP does not supersede NIP-56, which supports reporting content for the purpose of
direct moderation, in order to comply with laws or app store requirements. "Moderation"
as defined by this NIP is only relative to user preferences and should be interpreted
with the social graph in view to provide a better user experience.
Label Target
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The label event MUST include one or more tags representing the object or objects being
labeled: `e`, `p`, `r`, or `t` tags. This allows for labeling of events, people, relays,
or topics respectively.
Label Tag
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This NIP introduces a new tag `l` which denotes a label. A label MAY be an unqualified string indicating the type of content based on convention, a qualified string referring to a tag type within nostr, or a qualified string referring to a nomenclature external to nostr. Some examples:
-`review` - the publisher is leaving a review about the given entity.
-`#t/footstr` - the publisher thinks the given entity should have the `footstr` topic applied.
-`#p/<pubkey>` - the publisher things the given entity should be tagged with with `<pubkey>`
-`MeSH/D005528` - ["Foot"](https://meshb.nlm.nih.gov/record/ui?ui=D005528) from NIH's Medical Subject Headings vocabulary
-`GeoNames/3173435` - [Milan, Italy](https://www.geonames.org/3173435/milan.html) using the GeoNames coding system
-`ISO-3166-2/IT-MI` - Milano, Italy using ISO 3166-2.
As much as possible, fully-qualified labels should be used.
Other Tags
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The label event MAY include a `quality` tag with a value of 0 to 1. This allows for an
absolute, granular scale that can be represented in any way (5 stars, color scale, etc).
The label event MAY include a `confidence` tag with a value of 0 to 1. This indicates the certainty which the author has about their rating.