As examples, the tokens in Figure 2–10 are potential numbers, but they are not actually numbers, and so are reserved tokens; a conforming implementation is permitted, but not required, to define their meaning.
1b5000777777q1.7J-3/4+6.7J12/25/8327^193^4/56//73.1.2.6^-43^3.141_592_653_589_793_238_4-3.7+2.6i-6.17j+19.6kFigure 2–10: Examples of reserved tokens
The tokens in Figure 2–11 are not potential numbers; they are always treated as symbols:
//5+1+1-foo+ab.cd_^Figure 2–11: Examples of symbols^/-
The tokens in Figure 2–12 are potential numbers
if the current input base is 16,
but they are always treated as symbols if the current input base is 10.
bad-face25-dec-83a/bfad_cafefFigure 2–12: Examples of symbols or potential numbers^