A digital television (DTV) signal for use in a DTV receiver includes an extended text table (ETT) which includes a header and a message body. The header includes a table identification extension field which serves to establish uniqueness of the ETT, and the message includes an extended text message (ETM). If the ETT is an event ETT, the table ID extension field includes an event identification which specifies an identification number of an event associated with the ETT. On the other hand, if the ETT is a channel ETT, the table identification extension field includes a source identification which specifies a programming source of a virtual channel associated with the ETT. A section-filtering unit included in the DTV receiver is able to use table identification extension fields of a plurality of ETTs for section-filtering a pertinent event or channel ETT from the ETTs.