HP 4 FAMILY - Manual (Page 103)

The remaining fields should be set the same as in the
Format 0 Font Header for PCL Bitmapped Fonts, with the
following exceptions:
Font Type
Font type describes the font’s relation to symbol sets. For
Format 16 bitmap fonts, set this field to 3. A value of 3 is
used to identify a large (16-bit) font. All character codes 0 to
65534 are printable, except 0, 7 to 15, and 27 [decimal].
Access to those codes which are unprintable, yet have a
character defined, requires the use of the Transparent Print
Data command. In older font header formats, PCL 5
LaserJet printers use this field to determine the first and
last codes of the symbol set.
First Code
For Format 16 bitmap fonts, set this field to the first
printable character in the font. In older bitmap font
formats, PCL 5 LaserJet printers ignore this field.
Last Code
For Format 16 bitmap fonts, set this field to the last
printable character in the font. In older bitmap font
formats, PCL 5 LaserJet printers ignore this field.
One new data segment is defined for Format 16 bitmap
fonts:
Bitmap Resolution Data Segment
The bitmap resolution data segment is used to define the
x-resolution and y-resolution for the bitmap. This segment
is required for Format 16 bitmap fonts.
The structure for the bitmap segment is shown in
Table 2-13.
Printer-Specific Differences 2-67