CALS headers

CALS data must include a header block that is compliant with the conditions listed after the table below. The header block requires the following eleven header records to be entered at the top in the order shown.

Byte offset	Record ID and configurable value (all ASCII characters)
0000	srcdocid: optional
0128 (0x80)	dstdocid: optional
0258 (0x102)	txtfilid: optional
0348 (0x15C)	Figid: optional
0512 (0x200)	srcgph: optional
0640 (0x280)	doccls: optional
0768 (0x300)	Rtype: 1
0896 (0x380)	rorient: 000, 270
1024 (0x400)	rpelcnt: appropriate value
1152 (0x480)	rdensty: appropriate value
1280 (0x500)	notes: optional
1408 (0x580)	0x20 128 bytes
1530 (0x5FA)	0x20 128 bytes
1664 (0x680)	0x20 128 bytes
1792 (0x700)	0x20 128 bytes
1920 (0x780)	0x20 128 bytes
2048 (0x800)	Bitmap data

Header Block Conditions

The header must be 2048 bytes (fixed length).
Header records must be 128 bytes (fixed length).
Header records must start with a record ID.
Specified values for header record IDs must be entered in the separator's two character spaces: Colon (0x3a) and Space (0x20).
Header records that contain no directive value must be given "NONE" as their value.
Empty bytes in the header record and header block must be padded with spaces (0x20).