Search and Mark

 is a perk in Fallout: New Vegas given to you while you have Rex as a companion.

With this perk, food, chems, firearms, and ammunition within a short distance are highlighted when you zoom in.

Openable containers (i.e. refrigerator,metal box, etc) that have one or more of these items inside will also be highlighted. Once the items are removed, the container will no longer be highlighted. If any item(s) in this list is added to a container without said item(s), the container will be highlighted again.

A container will not be highlighted if there is only "junk" in it. It needs to have consumables (chems, food, drinks), weapons, and/or ammunition in the container.

You can also locate unopened Hollowed out rocks with this perk. Bizzarely, if you die while aiming, your dead body will sometimes glow green, probably due to the consumables and weapons you carry with you.

Bugs

 * Some killed creatures such as Lakelurks will be highlighted despite their bodies not containing anything the player can pick up. In the case of Lakelurks this may be due to the Lakelurk Shriek "weapon" they carry, which is classified as a real weapon with ammo but cannot be obtained by the player.