Should POUF-1 allow whitespace for prettified output?

In this conversation on #tuf, I'm in the process of renaming rust-tuf's interchange types to pouf, since that's more aligned with the tuf project. One complication though is that rust-tuf supports a prettified version of pouf-1 with JsonPretty. We use this to generate golden files to make sure code changes don't unintentionally change pregenerated metadata. It's much easier to read pretty json than minified json. However, according to pouf-1, this format uses OLPC's canonical json format, which disallows whitespace.

rust-tuf, and I'm guessing all the other implementations of POUF-1, can work with prettified metadata without issue. Should this be something that's formally supported? Or should implementations like this be treated as a non-standard POUF? If the latter, how should we refer to things like this? Should we avoid using the term POUF with things like this?

Start by reading the POUF-1 reference specification and OLPC's Canonical JSON definition linked in the issue, then review the rust-tuf JsonPretty implementation for the contrasting behavior. Done means deciding whether whitespace-prettified POUF-1 is formally supported and documenting how implementations should classify or refer to it.