Okay, "xmlmap" format is now deprecated. The sole reason for that is the 
int/float inconsistency with JSON. As JSON is the primary OKAPI output format 
and we often test new OKAPI methods using JSON only, this inconsistency can 
lead to backward-compatibility issues, as the one demonstrated in issue 127.

The revised "xmlmap2" format doesn't suffer from the int/float inconsistency 
issue. Additionally, we added some more improvements over the old format:

- "xmlmap2" is more compact and more readable than "xmlmap".
- "xmlmap2" XML element names are consistent with JSON datatypes specification 
(http://json.org/), whereas "xmlmap" element names were more "pythonic" 
(datatypes used in Python programming langugage).

Full list of changes:

- Both "int" and "float" datatypes were replaced by "number". Number should be 
parsed as integer or floating point number, according to the proper method 
documentation.
- "list" is now "array". "array" does not include separate "item" subelements 
to enclose each of its children, all child elements are placed directly as the 
children of the "array" element.
- "dict" is now "object". "object" does not include separate "item" subelements 
to enclose each of its key-value pairs, all value elements are placed directly 
as the children of the "object" element. Each of the object's children gets an 
additional "key" attribute.

This issue was closed by revision r409.

If your app uses "xmlmap" format, then you don't need to worry. The old 
"xmlmap" format will keep working as usual. We deprecate it simply because it's 
not as safe as the new one.