remove non dag-* variants

IPIP/0328-gateway-json-cbor-response-format.md

@@ -10,8 +10,8 @@
 
 ## Summary
 
-Add support for the [DAG-JSON], [DAG-CBOR], JSON and CBOR response formats in
-the [HTTP Gateway](../http-gateways/).
+Add support for the [DAG-JSON] and [DAG-CBOR] response formats to the
+[HTTP Gateway](../http-gateways/).
 
 ## Motivation
 
@@ -41,8 +41,8 @@ to storing and fetching CBOR and JSON in IPFS.
 
 ## Detailed design
 
-The solution is to allow the Gateway to support serializing data as [DAG-JSON],
-[DAG-CBOR], JSON and CBOR by requesting them using either the `Accept` HTTP header
+The solution is to allow the Gateway to support serializing data as [DAG-JSON]
+and [DAG-CBOR] by requesting them using either the `Accept` HTTP header
 or the `format` URL query. In addition, if the resolved CID is of one of the
 aforementioned types, the gateway should be able to resolve them instead of
 failing with `node type unknown`.
@@ -99,19 +99,12 @@ strict enough:
 
 ### Alternatives
 
-If we do not introduce  DAG-JSON, DAG-CBOR, JSON and CBOR  response formats in
-the gateway, the usage of IPFS is constricted to files and directories represented
+If we do not introduce DAG-JSON and DAG-CBOR, response formats in the gateway,
+the usage of IPFS is constricted to files and directories represented
 by UnixFS (DAG-PB) codec. Therefore, if a user wants to store JSON and/or CBOR
 in IPFS, they have to wrap it as a UnixFS file in order to be able to fetch it
 through the gateway. That adds size and processing overhead.
 
-In addition, we could introduce only DAG-JSON and DAG-CBOR. However, not
-supporting the generic variants, JSON and CBOR, would lead to poor UX. The
-ability to retrieve DAG-JSON as `application/json` is an important step
-for the interoperability of the HTTP Gateway with web browsers and other tools
-that expect specific Content Types. Namely, `Content-Type: application/json` with
-`Content-Disposition: inline` allows for JSON preview to be rendered in a web browser.
-
 Finally, we considered supporting pathing within both DAG and non-DAG variants
 of the JSON and CBOR codecs. Pathing within these documents could lead to responses
 with extracts from the document. For example, if we have the document:
@@ -143,8 +136,8 @@ However, supporting this raises questions whose answers are not clearly defined
 or agreed upon yet. Right now, pathing is only supported over CID-based Links,
 such as Tag 42 in CBOR. In addition, some HTTP headers regarding caching are based
 on the CID, and adding extraction pathings would not be clear. Giving users the
-possibility to retrieve JSON, CBOR, DAG-JSON AND DAG-CBOR documents through the
-gateway is, in itself, a progress and will open the doors for new tools and explorations.
+possibility to retrieve DAG-JSON and DAG-CBOR documents through the gateway is,
+in itself, a progress and will open the doors for new tools and explorations.
 
 ### Copyright
 

http-gateways/PATH_GATEWAY.md

@@ -186,8 +186,6 @@ For example:
 - [application/x-tar](https://en.wikipedia.org/wiki/Tar_(computing)) – returns UnixFS tree (files and directories) as a [TAR](https://en.wikipedia.org/wiki/Tar_(computing)) stream. Returned tree starts at a root item which name is the same as the requested CID. Produces 400 Bad Request for content that is not UnixFS.
 - [application/vnd.ipld.dag-json](https://www.iana.org/assignments/media-types/application/vnd.ipld.dag-json) – requests [IPLD Data Model](https://ipld.io/docs/data-model/) representation serialized into [DAG-JSON format](https://ipld.io/docs/codecs/known/dag-json/). If the requested CID already has `dag-json` (0x0129) codec, data is validated as DAG-JSON before being returned as-is. Invalid DAG-JSON produces HTTP Error 500.
 - [application/vnd.ipld.dag-cbor](https://www.iana.org/assignments/media-types/application/vnd.ipld.dag-cbor) – requests [IPLD Data Model](https://ipld.io/docs/data-model/) representation serialized into [DAG-CBOR format](https://ipld.io/docs/codecs/known/dag-cbor/). If the requested CID already has `dag-cbor` (0x71) codec,  data is validated as DAG-CBOR before being returned as-is. Invalid DAG-CBON produces HTTP Error 500.
-- [application/json](https://www.iana.org/assignments/media-types/application/json) – same as `application/vnd.ipld.dag-json`, unless the CID's codec already is `json` (0x0200). Then, the raw JSON block can be returned.
-- [application/cbor](https://www.iana.org/assignments/media-types/application/cbor) – same as `application/vnd.ipld.dag-cbor`, unless the CID's codec already is `cbor` (0x51). Then, the raw CBOR block can be returned.
 
 ### `Range` (request header)
 
@@ -598,10 +596,6 @@ The following response formats are selected according to the codec of the resolv
   - Directory
     - Generated HTML with directory index (see [additional notes here](#generated-html-with-directory-index))
     - When `index.html` is present, gateway can skip generating directory index and return it instead
-- JSON (0x0200)
-  - Bytes representing a JSON file, see [application/json](https://www.iana.org/assignments/media-types/application/json).
-- CBOR (0x51)
-  - Bytes representing a CBOR file, see [application/cbor](https://www.iana.org/assignments/media-types/application/cbor)
 - DAG-JSON (0x0129)
   - If the `Accept` header includes `text/html`: generated HTML with options to download DAG-JSON as-is, or converted to DAG-CBOR.
   - Bytes representing a DAG-JSON file, see [application/vnd.ipld.dag-json](https://www.iana.org/assignments/media-types/application/vnd.ipld.dag-json)