Barcode has been widely adopted across all major industries. A conventional barcode is a machine readable symbol consisting of a series of parallel, adjacent bars and spaces. The basic barcode structure features leading and trailing quiet zones, a start character, one or more data characters, one or more check characters (optional) and a stop character.

Barcode has a long development history that spanned half a century. During the evolution process, many formats have been developed and adopted by industries. Around a dozen of them are actively used today.

The term “symbology” is the scientific name for the barcode format. Different symbologies have different characteristics, such as the encoding efficiency and character set. The character set defines what kind of data the symbology encodes. Typically there are four types of character sets: (1) numeric. Only digits can be encoded. (2) alpha-numeric. The symbology is capable of encoding numbers, letters plus several punctuations. (3) full ASCII. All characters in the ASCII set, with value between 0 and 127, can be encoded. (4) Binary. Binary character set includes all 256 characters in a 8-bit single byte character set. Most of two dimensional symbologies are capable of encoding arbitrary binary data.

Some symbologies may impose length requirements. For example, UPC-A encodes the numeric data of exact 12 digits.

Two dimensional symbologies are usually capable of encoding thousands of characters.

Monterey Barcode Creator supports the following symbologies:

You can purchase symbology standards directly from AIM Inc. The web address of AIM is http://www.aimglobal.org.

Code 39 (also known as USS Code 39, Code 3 of 9) is the first alpha-numeric symbology developed to be used in non-retail environment. It is widely used to code alphanumeric information, such as the model number, etc. It is designed to encode 26 upper case letters, 10 digits and 7 special characters:

A, B, C, D, E, F, G, 
H, I, J, K, L, M, N, O, P, Q, 
R, S, T, U, V, W, X, Y, Z
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
-, ., *, $, /, +, %, SPACE.

Each code 39 symbol begins with a start character and ends with a stop character. Traditionally the start/stop characters are represented by asterisk character (*). Due to this reason, some applications include asterisks in the human readable text. The asterisks are not part of the encoded message and should not appear within the message.

Code 39 allows an optional checksum digit based on modulo 43 algorithm. The health industry has adopted the use of the check character for health applications and these types of barcodes are often referred as HIBC.

Property Code39OptionalCheckDigit specifies whether an additional check digit should be added to the barcode. Another property, Code39StartStopChars, when it is set to TRUE, adds the traditional start/stop characters (*) to the beginning and the end of the human readable text.

The Code 39 Full ASCII (sometimes also referred as Code 39 extended) is an extension to normal code 39. It is capable of encoding all 128 ASCII characters. It uses shift characters to combine two normal code 39 characters to encode a character not in the normal code 39 character set. The barcode generated is compatible with normal code 39, so a scanner must be configured to Full ASCII mode to read the barcode correctly.

Code 39 Full ASCII supports entering control characters using special character input method. You can use a back slash \ plus 3-digit decimal ASCII code to enter a control character. For example, the following input encodes digits 123, followed by a NUL character and letters abc:

Data Input: 123\000abc

Code39 HIBC is exactly the same as normal Code39, except that Code39OptionalCheckDigit property is set to TRUE. The standard also says that the starting character in the message must be a plus (+) symbol. Monterey Barcode Creator automatically adds this plus sign (+) if the encoded message does not meet this requirement.

The HIBC standard requires that the checksum digit to appear in the human readable. To satisfy this requirement, your program should explicitly set property ShowcheckDigit to TRUE to create a compliant HIBC symbol.

Setting Code39OptionalCheckDigit to FALSE does not affect the resulted barcode.

Codabar is a variable length symbology which encodes a character set of 16 letters ( 0-9, -, $, :, /, +). It is dubbed as NW-7 in Japan. You may choose one of these four start/stop characters in your symbol: A, B, C and D. If you do not specify the start/stop characters, Monterey Barcode Creator uses A and B as the start/stop characters, respectively. No check digit is required.

Code 93 is a variable length symbology that is capable of encoding all 128 ASCII characters. Code 93 offers higher density than Code 39. It has the same native character set as Code 39 (43 characters), but it uses additional 4 shift characters to encode other characters. Code 93 features 2 checksum characters. Start/Stop characters are also required.

Code 93 supports special character input method. See Code 39 Full ASCII section for details on how to escape control characters.

These are rather obsolete symbologies which only encode numeric data. There is no advantage to use them except for application backward compatibility. More information can be found at Morovia barcode library at http://www.morovia.com/education/.

The UPC-A barcode is the most common and well-known symbology in North America. You can find it on the cartons of virtually every consumer goods in your local supermarket, as well as books, magazines, and newspapers. A short form is called UPC-E. Each symbol may have 2-digit or 5-digit supplement to encode additional information.

UPC-A encodes 11 digits of numeric data along with a trailing check digit, for a total of 12 digits of barcode data.

A UPC-A number consists of four elements: (1) the Number System; (2) the manufacturer code; (3) the product code; (4) the check digit. Normally the number system digit is printed to the left of the barcode, and the check digit to the right. The manufacturer and product codes are printed just below the barcode, separated by the guard bar.

The UPC-E barcode is the short form representation of a UPC number. It reduces the data length from 12 digits to 6 digits by compressing the extra zeros. It is suited for identifying products with small packages.

A UPC-E barcode has 6 digits with an implied number system 0. The first 5 digits are calculated based on a conversion algorithm described below. The last digit is the check digit of the original UPC-A symbol.

Both UPC-A and UPC-E symbols allow for a supplemental two- or five-digit add-on barcode. This add-on barcode usually encodes a price or a sequence number. To include a supplemental message, append it to the main message with a vertical bar (|) to separate it from the main message. The supplemental message must consist of exact two or five digits.

EAN is designed by the International Article Numbering Association (EAN) in Europe. It is an extension to UPC-A to include the country information. The only difference between UPC-A and EAN-13 is that the number system in UPC-A is a single digit varying from 0 through 9, whereas an EAN-13 number system consists of two digits ranging form 00 to 99.

EAN-13 encodes 12 digits of numeric data along with a trailing check digit, for a total of 13 digits data.

An EAN-13 number consists of four elements: (1) the Number System; (2) the manufacturer code; (3) the product code; (4) the check digit. Normally the number system digit is printed to the left of the barcode, and the check digit to the right. The manufacturer and product codes are printed just below the barcode, separated by the guard bar.

EAN-8 is the short version of EAN-13, the same as UPC-E vs. UPC-A. While they look very similar, some differences exist. UPC-E does not explicitly encode the first digit (NS), while EAN-8 encodes all 8 digits. From barcode encoding/decoding perspective, an EAN-8 is not compatible with UPC-E. Moreover, although a UPC-E number can be converted back to UPC-A, this is not the case for EAN-8. There is no defined method for conversions between EAN-13 to EAN-8. An EAN-8 number is assigned in the same way as EAN-13.

An EAN-8 number contains 7 digits of message plus 1 check digit. The first two or three digits identify the numbering authority; the remaining 4 or 5 digits identify the product.

The International Standard Book Number (ISBN) has been invented for more than 30 years. It has experienced exponential growth and remarkable success. Today, every book, magazine, cassette and CD bear an ISBN number. Every item to be sold in bookstore is required to furnish an ISBN. The ISBN is used extensively by publishers, retailers as wells as libraries to manage inventory. The ISBN is represented through an EAN barcode, a.k.a. Bookland barcode plus an optional 5-digit (2-digit for magazines) add-on.

An ISBN is a 10 digit number preceded by the letters ISBN. The text is usually printed with OCR-A font. The 10-digit number is divided into four parts of variable length, which are separated by hyphens or spaces. The four parts are Group Identifier, Publisher Identifier, Title Identifier and Check Digit respectively. Note that the length of each part is not fixed, though the total length must be 10.

A Bookland symbol may have an optional 2-digit or 5-digit add-on symbol. To add the supplement, add them at the end of the main message and separate the two parts with a vertical bar(|), in the same way as the UPC and EAN supplements. For example, to encode an ISBN number 0-201-61595-9 with pricing information 53995, set the Message property to 0-201-61595-9|53995.

Note on 13-digit ISBN

Beginning on January 1, 2007, all 10-digit ISBNs are required to be re-expressed as a 13-digit number (EAN-13). To convert a 10-digit ISBN to 13-digit EAN number, drop the last checksum digit of the 10-digit ISBN number and add prefix 978 at the beginning. Calculate the EAN-13 check digit based on the result and append this checksum digit to the end of the result. To create the barcode, use EAN13 symbology instead and assign the 13-digit ISBN number to the message property.

Code 128 is a high-density alpha-numeric symbology. Since introduced in early 1980s, it has gained wide popularity in many industries. UCC/EAN derives its retail carton tracking standard UCC/EAN 128 based on Code 128 symbology.

Code 128 is a variable length, continuous symbology with multiple element widths. Every Code 128 symbol has a check character. Each character is encoded with three bars and spaces, in total 11 modules.

In the most recent standard ISO/IEC 15417, Code128 is extended to encode all 256 characters of a single-byte character set^[1]. The default character set is ISO 8859-1 (Latin Alphabet No. 1).

Code 128 standard also defines four function codes for special purposes. FNC2 is used to tell barcode reader to store the data and transmit with next symbol; FNC4 is used as a latch code word to switch into extended ASCII mode. FNC3 is reserved for future use. FNC1 is used in UCC/EAN128 to act as UCC/EAN-128 identifier and field delimiter.

Interleaved 2 of 5 is a high-density numeric symbology. Some applications require a modulo 10 checksum digit at the end of the message. Interleaved 2 of 5 uses an “interwinded” method to create barcodes and consequently it requires the data length to be even. In order to meet this requirement, Barcode Creator appends a MOD10 check digit when it finds that the input is in odd length. Otherwise, it encodes the data as is.

Note that this behavior has changed since version 3.6. Previously, check digit is added only when property I2of5OptionalCheckDigit is TRUE, otherwise a '0' is appended instead. The new implement allows you to enter 13 digits SCC-14 number to get a complete barcode with the check digit.

If the check digit is added, it always appears in the human readable text.

The input for Interleaved 2 of 5 allow spaces. The spaces are preserved in the human readable text but not encoded into the barcode. Fro example, the barcode below is created on input 0 07 70007 0723. Note that the last digit '9' is the check digit, which is calculated by the program.

Interleaved 2 of 5 is widely used to encode Shipping Container Code (SCC-14), which contains exact 14 digits. When it is used for encoding SCC-14 numbers, it is also called ITF-14.

You can add bear bars to the barcode by setting BearerBars to TRUE.

POSTNET (Postal Numeric Encoding Technique) encodes a US numeric address code (also called Zip code) which may contain 5, 9 or 11 digits - frequently referred as Zip, Zip+4 and Zip+6.

POSTNET is a height-modulated symbology which encodes the data in the height of the barcode instead of the width. Monterey Barcode Creator produces POSTNET barcode based on USPS standard. The height of each bar and the pitch between two adjacent bars are fixed and can not be modified. Changing NarrowBarWidth and BarHeight yields no effect. Although Monterey Barcode Creator produces human readable if you desire, keep in mind that USPS standard does not allow human readable text under the barcode.

The Monterey Barcode Creator accepts non-numeric input but filters them out at the time of the encoding. It adjusts the length by adding trailing zeros to meet the length requirement. You may take the advantage by assigning the full address line to the Message instead of passing only digits. For example, data input Monterey Park, CA 91755-1688 yields an identical barcode as message 917551688.