Abstract: A method of using an apparatus for identifying keys of a type that has a plurality of tags with adhesive on one side thereof for permitting attachment to a key. The tags are distinguishable from each other by a combination of color and shape. A reference sheet is also provided which has a plurality of indicia thereon, each respective indicia being of a color and shape to match the color and shape of the tags. The reference sheet has a space beside each one of the colored indicia for permitting an identification of an object to be placed in this respective space. This permits the respective colored indicia to be matched to a respective tag attached to a key thereby matching the key with the object to be locked or unlocked.