System and methods for communicating tracking information about tagged
items. A tagged item is a tangible item that carries a self-identifying
tag. The tracking information can be stored in the tag or in a document
that is accessible through an item tracking system. The tracking
information can be accessible by multiple consumers having different
levels of access. The methods include methods for masking redundancies in
the tracking information, filtering the tracking information, and
controlling access to the tracking information.