One variation of a system includes a tag including a panel defining an inner face; an outer face opposite the inner face and comprising a digital optical identifier; and a set of perforations interposed between the digital optical identifier and a perimeter of the panel; a tag housing molded around the perimeter of the panel and through the set of perforations in the panel; defining a body supporting the inner face of the panel; defining a rim extending from the body, encasing an edge of the panel; extending through the set of perforations in the panel; and extending over the set of perforations in the panel; and a barb extending from the body opposite the rim; a backing plate configured to receive the barb of the tag housing; and an applicator configured to drive the barb through an ear of an animal and into the backing plate.