An embedded data code comprises periodic tiles having occlusions. In one
embodiment, each tile is comprised of glyphs encoding a first code
system. The occlusions are comprised of information, such as glyphs
encoding a second code system, graphics, or text. The occlusions may
occur periodically in each tile. A reading device may be used to capture
an image of a portion of the substrate that includes a tile. A processor
then analyzes the image to determine the tile code pattern and decode the
tiled code.