What is Full reference line?

[wood5]

I got this email

Please also include the following information if it is not shown on the proof in order to effectively locate the charges:
- Your full name and address
- The account holders name if different
- Date of charge
- Charge amount + currency
- Full reference line
- If Credit Card: First 6 and last 4 digits of number + card provider
- If PayPal: Invoice ID

I do'nt know what is "Full reference line".
What is "Full reference line"?

[Asyn]

If you've any questions, reply to the mail and ask.

[wood5]

Customer not replay my email.
So I started ask in this board.

Can you inform me some customer email address?
It is possible, I sended mail to some wrong address.

[DavidR]

Please stick with your original topic https://forum.avast.com/index.php?topic=235169.0 or it will cause confusion and duplication of responses.