Documents to send with Passport for Online application

[Ankita1234]

I have applied for visitor visa for my parents. I have received letter for sending their passport to LA office.

But, I am not sure what documents, if any, I am suppose to send along with passport.

At this moment, I know I need to send :
- Passport
- Return envelope
- Confirmation letter I received from them
- Anything else?
- Two photographs (?? Not sure about this)

Please, someone help me with this ASAP. Many thanks in advance

- Ankita