Lexmark X864 Forms and Bar Code Technical Reference - Page 45

Byte 25 Field name ISSN Text Location 26 - 31 Reserved Range 00-05 (hex) 0-5 (dec) Default value 05 (hex) 5 (dec) Description Specifies location of ISSN text: 0 = Use default value 1 = Do not print 4 = Below symbol 5 = Above symbol Notes on ISSN, ISSN+2, ISSN+5: ISSN bar codes are EAN-13 symbols that encode the first seven digits of an ISSN (the checksum digit is not encoded), prefaced by a special "land of serial publications" country code (977), and followed by a 2-digit price code. The complete 8-digit ISSN is usually printed in human-readable format along with the symbol; this is in addition to the text that may appear showing the 13 digits actually encoded by the EAN-13 symbol. The bar code descriptor for ISSN contains two sets of fields for specifying the placement, typeface, and style of these two separate text strings. The data for an ISSN symbol consists of an 8-digit ISSN, followed by a two-digit price code, optionally followed by a two- or five-digit add-on code. If a two- or five-digit add-on code appears in the data, an EAN-13+2 or EAN-13+5 symbol will be generated, with the add-on code encoded in the +2 or +5 section of the symbol. Note that the last "digit" of an ISSN, the checksum digit, may be an "X" (ASCII 88). To enhance readability, "-" characters (ASCII 45) may appear anywhere in the data; they are ignored. The "-" character in the ISSN text printed with the symbol is always placed in a fixed position, not based on where a "-" may appear in the data. Since the last digit of an ISSN, the checksum digit, is not actually encoded in the symbol, it is required in the data only for the purpose of including it in the ISSN text printed with the symbol. The ISSN checksum digit is not verified or replaced by a calculation in the Forms and Bar Code Card. An invalid length (anything other than 10, 12, or 15 digits), or an invalid character (anything but a digit or a "-", except for an "X" in the eighth digit position) in the data produces an error message. Cursor positioning is handled the same as for other one-dimensional symbologies. If the Units bytes 5 or 8 are changed from their default values, then the Bar Height and Bar/Space Width parameters assume new dimensions, based on the new units. In other words, the parameters are in "units", and if the "units" measurements change, so does the physical printed bar code. If any of the parameters are set to 0 (zero), then the default value assigned in the table is assumed. One-dimensional bar codes 42