Interleaved 2 Of 5

Check digit: Optional
Use: Warehouse / Shipping and distribution / General purpose
Length: Variable length (any length)
Supported characters: 0 - 9
Class: Numeric-Only Symbology
Special notes: Encoding string should contain even number of digits. If that is not the case Barcode alpha software inserts leading zero.

Interleaved 2 of 5 is a higher-density numeric symbology based upon the Standard 2 of 5 symbology.
Interleaved 2 of 5 encodes any even number of numeric characters in the widths (either narrow or wide) of the bars and spaces of the barcode.
The symbology is called "interleaved" because a digit is encoded in the bars and the next digit is encoded in the spaces. The encoded digits are "Interleaved" together.