HP 4 FAMILY - Manual (Page 230)

Note The HP-GL/2 Kind1 value can be calculated from the sym-
bol set ID. The Kind1 value is the same value used for the
Symbol Set value field in the Font Header (refer to Chapter
11, Symbol Set of the PCL 5 Printer Language Technical
Reference Manual). The Kind1 value is computed by taking
the value of the value field for the symbol set, multiplying it
by 32, adding the decimal (ASCII) value of the termination
character (the symbol set ID character value) of the escape
sequence, and subtracting 64.
Font Descriptor Symbol Set Value =
(Escape Sequence Value Field Value * 32)
+
(Decimal Value of Escape Sequence
Termination Character - 64).
For example, to calculate the Kind1 value for the symbol
set 19M (M = ASCII 77):
Symbol set 19M = (19*32) + (77 -64) = 621
C-2 Symbol Set and Typeface Codes