customization list items for defects in qc REST api

We are developing qc mobile app for android using HP's rest api's.

we use customization list api to get the list values related to defects, but the problem is , xml tag names are getting changed if we switch projects.

example : for project A ,environment  tage name is "T_Environs_BSTB"  and for project B it is "Test Environment".

So we are not able to fetch list values because of different tag names .

our intention here is providing update feature for defects , so that user can go and select items from the lookup to update.   

so please let us know if any other api's are available or any other way to get the list values to provide update feature.

Thanks....