 Recall that Peirce thought signs signify their objects not through all their features, but in virtue of some particular feature. By 1903, for reasons related to his work on phenomenology, Peirce thought the central features of sign-vehicles could be divided into three broad areas, and consequently, that signs could be classified accordingly. This division depends upon whether sign-vehicles signify in virtue of qualities, existential facts, or conventions and laws. Further, signs with these sign-vehicles are classified as qualisigns, sinsigns, and legisigns respectively.