What a letter should carry

Your name.
A reply email.
The service page name.
The thing you want described: one finished line, one short note, one shelf of items you already listed, one page edge, counts you already have, or channel notes you already exported.
The company fact you want checked: the name, the address, or a number.

Passwords, payment cards, identity-document photos, and another person's personal data stay out of the letter.