Add L tag, allow self-labeling, split namespaces out

32.md

@@ -27,16 +27,21 @@ or topics respectively.
 Label Tag
 ----
 
-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:
+This NIP introduces a new tag `l` which denotes a label, and a new `L` tag which denotes a label namespace. A label MUST include a mark matching an `L` tag. `L` tags refer to a tag type within nostr, or a nomenclature external to nostr defined either formally or by convention. Some examples:
 
-- `review` - the publisher is leaving a review about the given entity.
+- `["l", "footstr", "#t"]` - the publisher thinks the given entity should have the `footstr` topic applied.
-- `#t/footstr` - the publisher thinks the given entity should have the `footstr` topic applied.
+- `["l", "<pubkey>", "#p"]` - the publisher things the given entity should be tagged with with `<pubkey>`
-- `#p/<pubkey>` - the publisher things the given entity should be tagged with with `<pubkey>`
+- `["l", "D005528", "MeSH"]` - ["Foot"](https://meshb.nlm.nih.gov/record/ui?ui=D005528) from NIH's Medical Subject Headings vocabulary
-- `MeSH/D005528` - ["Foot"](https://meshb.nlm.nih.gov/record/ui?ui=D005528) from NIH's Medical Subject Headings vocabulary
+- `["l", "3173435", "GeoNames"]` - [Milan, Italy](https://www.geonames.org/3173435/milan.html) using the GeoNames coding system
-- `GeoNames/3173435` - [Milan, Italy](https://www.geonames.org/3173435/milan.html) using the GeoNames coding system
+- `["l", "IT-MI", "ISO-3166-2"]` - Milano, Italy using ISO 3166-2.
-- `ISO-3166-2/IT-MI` - Milano, Italy using ISO 3166-2.
+- `["l", "relay", "review"]` - the publisher is leaving a review about a relay.
 
-As much as possible, fully-qualified labels should be used.
+`L` tags containing the label namespaces MUST be included in order to support searching by
+namespace rather than by a specific tag. The special `ugc` ("user generated content") namespace
+MAY be used when the label content is provided by an end user.
+
+`l` and `L` tags MAY be added to other event kinds to support self-reporting. For events
+with a kind other than 1985, labels refer to the event itself.
 
 Other Tags
 -----
@@ -49,21 +54,25 @@ The label event MAY include a `confidence` tag with a value of 0 to 1. This indi
 Example events
 --------------
 
-A report that an event contains nudity.
+A report that an event contains nudity. Note that NIP 56 is preferred for reporting content
+to clients, while labels are recommended for supporting distributed content moderation use
+cases.
 
 ```json
 {
   "kind": 1985,
   "tags": [
-    ["e", <id>],
+    ["L", "report"],
-    ["l", "nudity"]
+    ["l", "nudity", "report"],
+    ["e", <id>]
   ],
   "content": "",
   ...
 }
 ```
 
-A single event can apply multiple labels to multiple targets to support mass-tagging.
+A single event can apply multiple labels to multiple targets to support mass-tagging. Multiple
+namespaces may be used at the same time.
 
 ```json
 {
@@ -72,9 +81,14 @@ A single event can apply multiple labels to multiple targets to support mass-tag
     ["e", <id>],
     ["p", <id>],
     ["t", "chickens"],
-    ["l", "permaculture"],
+    ["L", "#t"]
-    ["l", "permies"],
+    ["L", "ugc"]
-    ["l", "farming"]
+    ["L", "com.example.labels"]
+    ["l", "chickens", "#t"],
+    ["l", "user generated content", "ugc"],
+    ["l", "permaculture", "com.example.labels"],
+    ["l", "permies", "com.example.labels"],
+    ["l", "farming", "com.example.labels"],
   ],
   "content": "",
   ...
@@ -87,7 +101,8 @@ A suggestion that multiple pubkeys be associated with the `permies` topic.
 {
   "kind": 1985,
   "tags": [
-    ["l", "#t/permies"],
+    ["L", "#t"],
+    ["l", "permies", "#t"],
     ["p", <pubkey1>],
     ["p", <pubkey2>]
   ],
@@ -104,7 +119,8 @@ that's the case.
 {
   "kind": 1985,
   "tags": [
-    ["l", "#t/bitcoin"],
+    ["L", "#t"],
+    ["l", "bitcoin", "#t"],
     ["r", <relay_url>],
     ["quality", 0.7],
     ["confidence", 0.2]
@@ -120,7 +136,8 @@ A plain review of a relay.
 {
   "kind": 1985,
   "tags": [
-    ["l", "review"],
+    ["L", "review"],
+    ["l", "relay", "review"],
     ["r", <relay_url>],
     ["quality", 0.1]
   ],
@@ -137,7 +154,8 @@ this spec provides for overlaying structured metadata on top of nostr.
 {
   "kind": 1985,
   "tags": [
-    ["l", "lightning/channel"],
+    ["L", "my-lightning-nomenclature"],
+    ["l", "channel", "my-lightning-nomenclature"],
     ["p", <pubkey1>],
     ["p", <pubkey2>]
   ],