On Aug 6, 2013, at 21:45, Joe Hildebrand <hildjj@xxxxxxxxxxx> wrote: > On 8/6/13 1:11 PM, "Carsten Bormann" <cabo@xxxxxxx> wrote: > >> If a CBOR application does require initial signature bytes for >> self-description purposes, I would suggest using something like >> >> 0xd8 0xf8 ...data item... >> >> which decodes as tag248(data item); we could define 248 as a no-op tag. > > Or a no-op simple value; we could easily pick one that did not generate a > valid first character for JSON. Well, simple values don't have "content". Using one as a signature would mean the data item ends right on the simple value, and the actual payload would be a second data item. I'd rather have a single data item that is just (ignorably) tagged. Yes, picking a tag number that encodes into a file signature that can't be a valid start for JSON (or many other kinds of things, e.g. UTF-8 text) is easy, as demonstrated above. Grüße, Carsten