How to get category attribute of a repository item property tag defined in repository xml.

[RJ. ()]

Suppose I have an item descriptor product and there are a property atgref and locale. Both are described as below :-
<property name="atgRef" column-names="ATGREF" data-types="string" category="identifier"/>
<property name="locale" column-name="LOCALE" data-type="string" category="identifier"/>

Now, In my code I have to find what kind of category this property is in since I have to show list of properties in a group made on basis of category. Like this I have to show group of properties in category physical specification, electric specification of a product then what is the ATG Api for Repository Item to fetch this category value of it.

Thanks in Advance,
RJ