A few of issues with the format-number() function.

1. The last example in 4.7.2 should say: returns "12.346E2"

2. 4.7.3 includes the rule:
"A sub-picture must contain at least one character that is an optional-digit-sign or a member of the decimal-digit-family."
I believe a new rule (or amendment) is required to say:
"The mantissa part must contain at least one character that is an optional-digit-sign or a member of the decimal-digit-family."
e.g. so that a pattern such as ".e99" is not allowed.

3. 4.7.3 includes the rule:
"A sub-picture must not contain a grouping-separator-sign adjacent to a decimal-separator-sign."
Should there in fact be a rule to say that a grouping-separator-sign is not allowed at the end of an integer part?
e.g. consider the pattern "#,".

4. There is no rule to say that grouping-separator-signs can not be adjacent. Should there be? If this is allowed, I believe that by following the algorithm in 4.7.4 (Analysing the picture string) currently duplicates get ignored e.g. format-number(12345.678, '#,,###') returns 12,345