Where's the inflection information in official dictionaries?

Hey guys, not sure if this have been asked or not.

But recently I have dedrmed and unpacked (using KindleUnpack) the official dictionary New Oxford American Dictionary. I expected there's <idx:iform> tags (for word inflections) in the ouput html file, but I searched the whole file and there was none.

So, Anyone know how official dictionaries handle inflections? Or if the KindleUnpack plugin simply ignored the <idx:iform> tag?

Actually, I need the inflection data in official dictionaries to make my own dictionary. And I have programming skills. So any help would be appreciated.