Letter from Vault-Tec (Fallout 3)

A  can be found randomly in the mailboxes of ruined houses across the Capital Wasteland.

There are two versions of the letter. One informs the recipients that their application to get into a Vault has been denied, however Vault-Tec will retain their deposits in case an opening appears. Another version is addressed to Mr. and Mrs. Gomez, informing them that their application to get into Vault 101 was accepted. This was most likely delivered to the ancestors of Officer Gomez, whom the Lone Wanderer meets in Vault 101.

Locations
The "accepted" version can be found in a mailbox in Springvale, and the ruins out side of Tenpenny Tower. The "rejected" version may spawn randomly in various mailboxes across the Capital Wasteland.