TLC 39

Telecommunications Industry Forum (TCIF) Linked Code 39 (TLC 39) was invented in 2001 by Frederick Schuessler of Symbol Technologies, Inc. This symbology gave many companies the ability to continue to use their existing linear code scanners while transitioning to more sophisticated equipment that could also read the two-dimensional (2-D) components.

The symbol combines a Code 39 - Regular linear component that has an added linkage flag with a MicroPDF417 2-D stacked component that omits the leading data identifier (S). There is no separator pattern between the components and no required amount of space between them. The linkage flag appears as a set of five bars and four spaces (representing the letter T) to the right of the Code 39 symbol. Apart from this linkage flag and the omission of the data identifier, TLC 39 inherits its characteristics from Code 39 and MicroPDF417 and is decoded as these symbols would typically be.

TLC 39 is defined in United States Patent Application Publication - US 2001/0045461 A1.