There is a long-standing requirement for the ability to format floating point numbers in scientific notation. This appeared as a requirement for XSLT 2.0, but it has never been satisfied.
Note that the Java DecimalFormat class, on which format-number() is based, accepts pictures such as
to request scientific notation.
At their meeting of 2012-09-25, the Joint WGs agreed to make this a candidate requirement for F&O 3.1
Note: The WG agreed we will also need other data formats frequently found in Web applications, such as Unix/RFC timestamps, HTML 5 date/time for example.
Notes from meeting #523:
Q2.9.20 Bugzilla Bug 18447, [XQ31ReqUC] Formatting numbers in
Liam: may be wanted for json in practice along with Unix-format (RFC)
Mike Kay: if you take JSON use cases seriously, Web services and HTTP
headers will emerge.
Jonathan: when it emerges we can consider it.
scientific notation (read and write)
YES, scientific notation (required in JSON)
This will be a MAY requirement.
This bug has been re-directed to the F&O 3.1 document, as the requirement has been accepted (as a MAY requirement).
The specification of format-number() in XPath 3.1 has been extended to satisfy this requirement. The bug entry is therefore being closed as resolved/fixed.