WikiPedia. Unicode Planes. Currently, about ten percent of the potential space is used. Furthermore, ranges of characters have been tentatively mapped out for every current and ancient writing system (script) the Unicode Consortium has been able to identify.[1] While Unicode may eventually need to use another of the spare 11 planes for ideographic characters, other planes remain. Even if previously unknown scripts with tens of thousands of characters are discovered, the limit of 1,114,112 code points is unlikely to be reached in the near future.
The Unicode Consortium has stated that the limit will never be changed.[2] Sometimes, the terms “astral plane” and “astral characters” are used informally to refer to the planes above the Basic Multilingual Plane, that is, planes 1–16 and their characters.[5] A map of the Basic Multilingual Plane. The first plane, plane 0, the Basic Multilingual Plane (BMP), is where most characters have been assigned so far. A map of the Supplementary Multilingual Plane.