|The following is based on Fallout: Brotherhood of Steel and has not been confirmed by canon sources.|
Found a ring, on the inside there are some engraved markings that read "9-29-2001, H&H". What could this mean?”— In-game description
A wedding ring, with what seems to be a diamond and inscripted with the date 2-29-2001. The first three digits are the code used in combination with the console keycard to open the door to Laboratories Three.
Secret Vault - Laboratory Two, in the East room on a console near a dead vault dweller.