|Out of universe information|
The NAVI Bit (Navigational Assist Vector Information Bit) was introduced by Kevin Flynn by the insistence of Clu in TC29. The sudden emergence of the ISOs flooded Tron City with undirected programs who wandered aimlessly, often into secured sectors in search of shelter and provisions.
A Bit variant was created to mark a simply binary A to B path node. As part of each ISOs registration, the NAVI Bit was added to each disc to guide ISOs through the massive metropolis to keep them away from secured sectors while helping them find a direct path to their daily needs.
As the NAVI Bit was designed to function only within limits of Tron City, it would go offline outside the city's boundaries.