On 26/09/2019 09:56, Lassi Kortela wrote:

> Once again we agree but Alaric phrased it better than I did :)

Aw *blush*

> Personally, I find most advisory notes in specifications to be a bit of
> a cargo-cult thing.
[...]

Good point. I suppose the reason I'd like such notes not in a format
spec is that the purpose of the spec is to define a line between valid
and invalid values (and, perhaps, to assign some kind of semantics to
valid values as well); there might be a place to mention some likely
implementation limits you might encounter, but it should be in an
appendix IMHO so to make it clear it's not part of the definition of a
valid value.

Also perfectly valid is for a spec to also standardise the declaration
of implementation limits, as part of also specifying what counts as an
implementation. It might say "Valid implementations are welcome to limit
string size, integer range, whether or not they support floats, string
character set, and total message size", thereby clearly placing an
implementation that doesn't support characters as invalid, and giving
users of the format some useful guidance that using long strings, large
integers, floats, unusual character sets, and large messages might cause
problems so should be avoided unless necessary. It also means that
implementations have a defined set of axes to be compared along, which
can be helpful when choosing them.

--
Alaric Snell-Pym   (M7KIT)
http://www.snell-pym.org.uk/alaric/