[Cbor] Actual features used: EDN Usage in RFCs

[Rohan Mahy <[e-mail]>]

Hi All,

There are 53 RFCs that reference RFC8610
<https://datatracker.ietf.org/doc/rfc8610/referencedby/> (35 normative and
18 informative).

I manually perused *all of them* for EDN looking for usage of specific
features. Here are my findings:

*RFC 8949 diagnostic notation features*
indefinite length arrays, maps — one instance of indefinite length array
found in RFC 9891.
indefinite length strings — no instances found
b32, h32 — no instances found

*RFC 8610 EDN features*
whitespace in h’’ and b64’’ (§G.1) — widely used
text in byte string notation (§G.2) — found in RFC 9052 (kid in protected
header), perhaps in others.
embedded CBOR (§G.3) — used in several COSE documents: RFC 9052, RFC 9338;
plus RFC 9594, RFC 9891
concatenated strings (§G.4) — no instances found
hexadecimal integers (§G.5) — found in 1 RFC
octal and binary integers (§G.5) — no instances found
hexfloat notation (§G.5) — no instances found
/comments/ outside of quoted strings (§G.6) — universally used
/comments/ inside h’’ (§G.6) — one use (/x/) in Figure 4 of RFC 9528
/comments/ inside b64’’ (§G.6) — doesn’t work
# comments (alluded to in §G.6) — RFC 9886

*Features in draft-ietf-cbor-edn-literals*
ellipsis (…) — used in RFC 9770, RFC 9880, RFC 9942, RFC 9943†
// comments — no instances found
extra trailing comma — one example found in RFC 9526 (possibly
unintentional)

†Note: RFC 9443 contains a travesty of EDN, with unquoted text strings and
nill instead of null

*RFC 8742* introduced CBOR/ EDN sequences

Thanks,
-rohan