Broadcast information is classified in categories to facilitate user selection
and filtration of the broadcast information which is processed for presentation
to the user. The broadcast information is transmitted in the form of a meta frame
and one or more category frames which are repeated in a continuous cycle. Meta
frames and category frames are distinguished and identified by major and minor
codes following a frame starting delimiter. The meta frame contains a description
of each of the available categories, together with an identification of respective
category major and minor codes, the frequency on which the respective category
frame is transmitted if multiple frequencies are employed, and the relative position
of the respective category frame within transmission cycle. If multiple frequencies
are employed, the meta frame may be repeatedly broadcast on a base frequency while
subsets of the category frames are transmitted on different frequencies, or the
meta and category frames may be repeated in sequence on all frequencies but with
varying offsets. Upon user selection of a category, the category information within
the meta frame is employed to construct or key a filter for the broadcast information.
The selected category frame data is received and added to a local database, formatted,
and presented to the user.