Include streaming string data, other wording improvements.

Author: handrews

versions/3.0.4.md

@@ -171,7 +171,7 @@ Two formats, `binary` and `byte`, describe different ways to work with binary da
 * `binary` is used where unencoded binary data is allowed, such as when sending a binary payload as an HTTP message body, or as part of a `multipart/*` payload that allows binary parts
 * `byte` is used where binary data is embedded in a text-only format such as `application/json` or `application/x-www-form-urlencoded`
 
-The `maxLength` keyword can be used to set an upper bound on the length (in octets) of a binary payload; otherwise, a binary payload SHOULD be interpreted as a stream of indeterminate length.
+The `maxLength` keyword MAY be used to set an expected upper bound on the length of a streaming payload.  The keyword can be applied to either string data, including encoded binary data, or to unencoded binary data.  For unencoded binary, the length is the number of octets.
 
 Note that the encoding indicated by `byte`, which inflates the size of data in order to represent it as 7-bit ASCII text, is unrelated to HTTP's `Content-Encoding` header, which indicates whether and how a message body has been compressed.