role play, 2) index and reference locations in the signing space in front of the signer, on the head and trunk, and on the non-dominant hand, 3) different movement repetitions, 4) size and shape delineation techniques using handshapes and extensions of movements of the hands (Size and Size Specifiers, SASS), and 5) a feature common to most sign languages: an extensive formal system of classifiers used in verbs/predicates. Classifiers are handshapes used to describe things, handle objects, and represent a few semantic classes that are regarded by IS signers to be widespread in sign languages, helping them to overcome linguistic barriers. It has been noted that signers are generally better at interlingual communication than non-signers, even using a spoken lingua franca. A paper presented in 1994 suggested that IS signers "combine a relatively rich and structured grammar with a severely impoverished lexicon". Supalla and Webb (1995) describe IS as a kind of a pidgin, but conclude that it is "more complex than a typical pidgin and indeed is more like that of a full sign language". Recent studies of International Sign Simplification of signs in IS can vary between interpreters (one can choose a simplification over a much longer explanation), and because of this, certain information can be lost in translation. Because sign language relies heavily on local influences, many Deaf people do not understand each other's signs. Furthermore, cultural differences in signs can vary even within borders. In these cases, many Deaf people revert to fingerspelling and gestures or mime, which has its own variations based on similar sign language properties. The World Federation of the Deaf (WFD) has raised concern about the issues with simplification and standardization, and that it limits a sign to a single meaning or word, thus losing all natural forms of the initial meaning. An ethnographic study notes that there is some controversy among deaf people about how accessible IS is to deaf people from different places; it also observes that many deaf people are nevertheless highly motivated to do the work of communicating across linguistic and other differences. Examples WFD homepage – contains a short QuickTime video in IS with English subtitles. Digital version of Gestuno: International Sign Language of the Deaf/Langage Gestuel International des Sourds — contains original IS signs (many now outdated) in photograph form Short International Sign Language Dictionary web archive EU sample dictionary of IS (sematos) European Union on