Ah, if you just want to make the UTF-8 requirement less strict for simpler decoders, that can be actually okay. My belief is more about legacy encodings like Shift_JIS.
I never seriously tried to fit any graph struture into a serialization format, so I don't yet have a very concrete opinion besides from what was already said. (I'm not even sure Concise had a good approach for that...)
> a common enough occurrence
Do you have a concrete figure about "common enough"? Otherwise we are only talking through anecdotal evidences (not necessarily bad though!). At least in my experience, graph structures do occur from time to time but almost all of them can be easily rewritten to non-graph form because they are typically DAGs and obviously ranked (i.e. its preferred topological order forms partitions of different nodes). The general graph that requires something like references was very rare.
I disagree, although I do not believe that this disagreement should have to affect some file formats, since some file formats should not need to care about the character encoding, except perhaps specific details, e.g. that ASCII bytes have ASCII meaning and non-ASCII bytes have non-ASCII meaning (which is true of UTF-8 and of some others).
> IEEE 754 doesn't define any textual format while it does have binary decimal formats. The correct wording should have been that numeric scalars follow a specific grammar to be interpreted as an IEEE 754 binary64 number in the data model.
OK. Although it seems clearly enough, probably the document should specify explicitly its working anyways, like you mention.
> There are several formats that do try to support native graph types, including YAML and Concise [1]. So that is hardly new.
I had seen Concise as well, and I have criticisms of that too. I did forget it though as I was writing my message.
I did have a idea to add a reference type too (you can see my other comment about TER and ASN.1X), although I would have it to not have the same meaning as the data it references (therefore meaning that it cannot result in cyclic graphs, even if it references itself). I think I should not have remote references, though. Concise encoding seems to have it have the same meaning as the data it references, and I think it is useful to not do this (you could use compression if you want to deal with many of duplicated data).