Intenational Sign is signing used in the communication of the Deaf people from different national sign languages.

Contrary to the common understanding that sign language is universal, Deaf communities all over the world use different national sign langauges. Due to the visual modality of sign languages, there are many common traits in the grammars of sign languages and the main differences only occur in the lexicon. Therefore, compared to the speakers of different spoken languages, it is much easier for the signers who use different sign languages to communicate.

The researches about sign languages show that there are also more similarities in lexicons of sign languges than in lexicons of different spoken languages. Due to the visual modality of sign languages, there are more directly or indirectly motivated signs which meaning can be guessed directly or indirectly from its form.

International sign emerging in the contact of two or more sign languages uses these similarities in the grammars and lexicon. The signs, which form refers to the designated object, quality or action most directly, are selected from different sign languages.

In the second half of the last century the attemptions were made to standardize internationally used signing. A sign language to be used at the international Deaf meetings, was created artificially. It was called Gestuno and it was like Esperanto for spoken language speakers.

This artificially created language was not widely used in the Deaf communication. Instead, Deaf people rather communicated in ASL.

International Sign is not a language described by certain grammar rules or signs fixed in a dictionary. Its rather a form of signing related to a certain situation, its participants and their language usage and forming in contact of different sign languages in a certain situation. When different sign languages come in contact, the signs comprehensible for everyone and most visual grammatical structures are selected, the elements of pantomime and body language are used. Therefore, International Sign may be more or less influenced by certain national sign langugages.

The dictionary contains just a small selection not an extensive list of signs possibly more widespread internationally. Also, internationally used fingerspelling alphabet for writing the words by different hand forms is added.

Knowing different sign languages helps to learn and use International Sign.