The captives communicated by notes stuffed in an open pipe in the bathroom and by hand signals in a language devised by Anderson.

Quenya is a fictional language devised by J. R. R. Tolkien.

You may also be looking for Interlingue, more commonly known as Occidental, a little-used auxiliary language originally devised by Edgar de Wahl.

N'Ko is a literary language devised by Solomana Kante in 1949 as a writing system for the Mande languages of West Africa.

Taliska is a constructed language devised by J. R. R. Tolkien.

Words appeared in "shortline," the compressed language devised for small-screen imagery.

Solresol is a constructed language devised by François Sudre, beginning in 1827.

The ideas underlying actor-lab are derived from the event-driven, message-passing computer languages that began with the actor based languages devised by Hewit.

Tolkien intended the name Gondor to represent a sample of Sindarin, an Elven language devised by him, and within the books used by the Dúnedain for nomenclature.

Then it's on to the future, represented in the pictographic language devised by the Search for Extraterrestrial Intelligence Institute in the 1970's.