In the
Unicode standard, a
plane is a continuous group of
65,536 (= 2
16)
code points. There are 17 planes, identified by the numbers 0 to 16
decimal, which corresponds with the possible values 00–10
hexadecimal of the first two positions in six position format (
hhhhhh). The planes above plane 0 (the Basic Multilingual Plane), that is, planes 1–16, are called “supplementary planes”, or humorously known as “
astral planes”. As of Unicode version 8.0, six of the planes have assigned code points (characters), and four are named.