2 of 5 Interleaved

Barcode-Glossary

2 of 5 Interleaved

Origin

The code 2 of 5 Interleaved was developed in 1972 by Intermec, based upon the code 2 of 5 Industrial. The code 2 of 5 Interleaved belongs to the code family 2 of 5, that still chiefly consists of the codes "2 of 5 Industrial" and "2 of 5 Matrix".

Furthermore, there are a few more variants that have more or less prevailed.

Symbol Examples

Example of a code 2 of 5 Interleaved Symbol with nine functional characters (123456789) and one symbol check character (5):

Interleaved Symbol with nine functional characters

Example of the nesting of the digit pairs:

1st digit of the digit pair (bar coding)
2nd digit of the digit pair (space coding)
Start and/or Stop-Pattern

Symbol Designations

The code "2 of 5 Interleaved" is sometimes also called

  • 2 of 5 Interleaved (VBCD: 2 of 5 Interleaved) or
  • Interleaved 2 of 5 or
  • I 2 of 5 or
  • USD-1.
  • 2/5i and/or 2/5 interleaved (unofficial notation)

The two digits 2 and 5 express that each barcode font consists of 2 wide Elements, with altogether 5 elements. The term interleaved indicates that, Bars and Spaces within a character display, in a nestled way, 2 functional characters (see symbology description further down).

Areas of Application & Branches of Trade

  • Parcel services
  • Industrial applications

Classification

Advantages / Potencies

Disadvantages / Shortcomings

  • Low printing tolerance, as the Spaces carry information.
  • Because of the overlapping (nesting), the digits can only be displayed in pairs.
  • Continuously decreasing importance.

Codeable Character Set

  • Digits 0 1 2 3 4 5 6 7 8 9
  • The start/stop-character is automatically generated by the "Visual Bar Code Designer" (start/stop-pattern).

Symbol Properties

  • Code type: continuous (all Bars and Spaces contain information).
  • Elements per symbol character: 5, 2 wide ones and 3 narrow ones, displayed either in form of 5 Bars or 5 Spaces.
  • Self-checking characters: yes (the characters are intrinsically safe, meaning that a change within the character is detected to be an error).
  • Symbol Width: variable, even number of characters (the number of data characters within the symbol can be, according to existing agreements, firm, variable or variable up to a defined maximum.
  • Ratio (ratio between wide and narrow elements): the ratio should range between 2.0 : 1 and 3.0 : 1.
  • Bi-directionally readable: yes (the barcode symbol can be read in two directions, i.e. forwards or backwards).
  • Check Character: an optional  check character (by using a check character – symbol check digit – substitution errors can nearly all be detected).
  • Character Density: 14 to 18 modules for two characters each, according to the ratio between wide and narrow elements.
  • Necessary characters carrying no functional information: 8 to 9 modules, according to the ratio between wide and narrow Element.

Check Digits & Data Security

The five Elements, the Bars as well as the Spaces, each consist of 2 wide and 3 narrow elements. That way, each Character of the code 2 of 5 Interleaved is self-checking and thereby already guarantees a high level of security against misread.

In case of applications that require a high level of Data Security, a Symbol Check Digit has to be entered immediately after the last Data Characters and directly before the Stop Pattern (stop character - will be automatically generated by the "Visual Bar Code Designer", if necessary).

The number of characters to be encoded, including the check character, should be even. A leading zero can be inserted, should it be required (even number of characters).

Symbol Description

A symbol – starting from the left – consists of:

  • a leading Quiet Zone
  • a Start Character (Start-Pattern)
  • one or more character pairs, representing data (including the optional, Symbol Check Digit, that is generated by the "Visual Bar Code Designer", if necessary),
  • a Stop Character (stop-pattern)
  • a closing quiet zone
  • Human Readable Text
    A human readable translation of the data character encoded in the symbol
    (and possibly the check digits) should usually be printed along with the symbol.
    The size of the characters and the font type are not specified. As long as the quiet zones are not touched, the human readable text can be printed at any given spot near the symbol. Usually, the human readable text is situated below the symbol.

Special Applications

For the special applications, described below, the code 2 of 5 Interleaved serves as a basis. For the differentiation as against the standard code, special check digit calculations, character quantities, etc. are mandatory.

  • USPS tray label (VBCD: USPS tray label)
    Since July 1997, special mail items of the United States Postal Services are provided with a special label so that a better sorting of mail items can be performed. On this label, there is a barcode symbol based upon the code 2 of 5 Interleaved. Size, position, etc. are exactly specified by the USPS.