Make charter more explicit about composability and unsigned_varint dependency

README.md

@@ -1,25 +1,34 @@
 # IETF Multiformats Working Group
 
 Multiformats are a collection of self-describing data formats that consist of an
-inline data header and a data value. Multiformats have binary and text-based
-representations and are used to express base encodings (multibase),
-cryptographic hashes (multihash), cryptographic keys (multikey), network
-addresses (multiaddr), and a variety of other binary serialization formats
-(multicodec).
+inline data header and a data value. They are composable in that some of the
+more complex forms take another multiformat header/value tuple as value,
+recursively. Multiformats are designed to compose data into binary streams with
+both inline header values (called [multicodecs][1]) and corresponding data
+values, with the exception of multibase, which base-encodes any binary and
+prepends its inline header to the target encoding rather than to the binary data
+value being encoded.
 
 The scope of this Working Group is to discuss these formats as they relate to
-standardization at the IETF. Specifically, the group is currently focused on the
-standardization of two Multiformats: Multibase and Multihash. The input
-documents for these two Multiformats are:
+standardization at the IETF for wider and safer usage. Specifically, the group
+is currently focused on the standardization of the two most generally-useful
+multiformats: multibase and multihash. The input documents for these two
+multiformats are:
 
 * https://datatracker.ietf.org/doc/draft-multiformats-multibase/
 * https://datatracker.ietf.org/doc/draft-multiformats-multihash/
 
 Outputs for the group will be:
 
-* A Multibase specification
-* A Multihash specification
-* A registry for Multiformats with initial entries for Multibase and Multihash
+1. An RFC specifying multibase usage
+2. An RFC defining an independent multibase registry and populating it with
+   today's already-implemented stable and final values
+3. An RFC defining a registry-group for all the multicodecs, empty at
+   inception, with registration process and group-wide constraints on
+   registration values
+4. An RFC specifying multihash usage
+5. An RFC defining a multihash registry within the multicodecs registry group
+   and populating it with today's already-implemented stable and final values
 
 The outputs from this Working Group are currently being used by various groups,
 including the W3C Verifiable Credentials Working Group, W3C Decentralized
@@ -32,9 +41,12 @@ listed in this section as well as other relevant groups as the work progresses.
 
 Items that are out of scope for the group include:
 
-* Standardizing Multiformats that are not explicitly listed in the charter.
-* Creating or standardizing new data formats identified by a Multiformat byte
+* Standardizing other multiformats that are not explicitly listed in the
+  charter.
+* Creating or standardizing new data formats identified by a multicodec byte
   header.
 * Determining whether one data format is better than another data format.
-* Changing current Multiformat header assignments in a way that breaks backward
+* Changing current multiformat header assignments in a way that breaks backward
   compatibility with production deployments.
+
+[1]: https://ipfs.io/ipfs/QmXec1jjwzxWJoNbxQF5KffL8q6hFXm9QwUGaa3wKGk6dT/#title=Multicodecs&src=https://raw.githubusercontent.com/multiformats/multicodec/master/table.csv