When I make a new DocType and try to set its fields.
if a field name have small and capital letters like:
when I click save and refresh, it get automatically converted all letters to small case:
How to solve this problem ?
It can’t be set the uppercase because it’s defined in the core.
I did it before but I can’t remember how I did it…
I remember changing the doctype json file and the field names in the database
but I’m trying to do so but can’t make it now 
Please check the code. It’s defined in the doctype.py