Sign languages, like spoken languages, organize elementary, meaningless units (once called cheremes in the case of sign languages, by analogy to the phonemes of spoken languages) into meaningful semantic units. This is often called duality of patterning. As in spoken languages, these meaningless units are represented as (combinations of) features, although often also crude distinctions are made in terms of Handshape (or Handform), Orientation, Location (or Place of Articulation), Movement, and Non-manual expression. More generally, both sign and spoken languages share the characteristics that linguists have found in all natural human languages, such as transitoriness, semanticity, arbitrariness, productivity, and cultural transmission.