Commodore 128 System Manual page 300

A decimal point (.) symbol designates the position of the decimal
point in the number. There can be only one decimal point in any
format field. If a decimal point is not specified in the format field,
the value is rounded to the nearest integer and printed without
decimal places.
When a decimal point is specified, the number of digits preceding
the decimal point (including the minus sign, if the value is
negative) must not exceed the number of hash signs before the
decimal point. If there are too many digits, an overflow occurs
and the field is filled with asterisks (*).
A comma (,) allows placing of commas in numeric fields. The
position of the comma in the format list indicates where the
commas appear in a printed number. Only commas within a
number are printed. Unused commas to the left of the first digit
appear as filler character. At least one hash sign must precede
the first comma in a field.
If commas are specified in a field and the number is negative,
then a minus sign is printed as the first character, even if the
character position is specified as a comma.
A dollar sign ($) symbol shows that a dollar sign will be printed in
the number. If the dollar sign is to float (always be placed before
the number), at least one hash sign must be specified before the
dollar sign. If a dollar sign is specified without a leading hash
sign, the dollar sign is printed in the position shown in the format
field. If a plus or minus sign are specified in a format field with a
dollar sign, the program prints the sign before the dollar sign.
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