Is it possible to extract custom entity ?

[HarshitDaftary]

I am working with a chatbot application. i would like to extract custom entity ( Slot / Entity ) custom entity from user's input. For ex: we can define a custom entity as Car Type. If user says " I own a Mercedes Benz car" . The machine will get Car Type as Mercedes Benz. And If user says "I own a car" , machine can validate that the "car type" is missing.

[danechitoaie]

I'm interested in this too.