Use ||number|| to select a symbol in position number of the current font. The characters |'| or |"| at the beginning of number denote octal or hexadecimal base, respectively.
Use |
1| number|| to produce non-aligned digits
like
11982. Works in text and math and honours spaces in
the argument if used in text. Don't try to put other characters in the
argument, the result would be unpredictable and may change in later
releases.