When submitting a support ticket, what type of proof for my account should be attached?

• If retail software is registered to the account, attach a digital photo or scan of the CD Key registered to the account. Write the Steam account username on the quick reference card or CD Key sticker below the code in permanent ink.
  Examples:
  
  

• If a game was purchased through Steam with a credit card, please provide the following:
  • The Card Type (Visa, MasterCard, Discover, American Express)
  • Full Name on the Card
  • Expiration Date
  • The last four digits of the credit card number - Do not provide the full credit card number
• If a game was purchased through Steam using a PayPal account, please provide:
  • The Billing Name on the PayPal Account
  • The full Billing Address on the PayPal Account
  • The PayPal PayerID
  • The Invoice ID and the Transaction ID

If any other type of payment was used, please explain this in the support ticket.