Major technical comment: identifier length

2.2 Initial definitions
The definition of "query variable" says that there are infinitely many.
This is not computationally realistic.  It would be better to agree on
some suitable number of characters that all conforming implementations
must support as a minimum.  This would provide guidance to users in
writing portable queries.  Experience in the SQL community shows that
this issue can be a source of on-going problems, owing to the
differences between implementations regarding supported length of
identifiers.  An explicit requirement should be stated in Appendix B,
"Conformance".

Fred Zemke