Extension to cover AC-3, mobile DVB-T and backwards compatible modifications in the light of implementations experiences. To bring into line with ETR revision Specification of Service Information (SI) data which forms part of DVB /MPEG-2 bitstreams, in order that the user can be provided with inform ation to assist in selection of services and/or events within the bits tream, and so that the Integrated Receiver Decoder (IRD) can automatically configure itself for the selected service. SI is specified in ISO/IEC 13818-1 as Programme Specific Information (PSI). This specification complements the PSI by providing data to aid automatic tuning of IRDs, and addditional information intended for display to the user, mainly in text form. The manner of presentation of the information is not specified, and IRD manufacturers have freedom to choose appropriate presentation methods. It is expected that Electronic Programme Guides (EPG) will be a feature of Digital TV transmissions. The definition of EPG is outside the scope of the SI specification, but the data contained within the SI specified here could be used as basis for an EPG. The present specification describes Service Information (SI) for use in broadcast MPEG-2 bitstreams. The MPEG-2 System layer specifies SI which is referred to as Programme Specific Information (PSI). The PSI data provides information to enable automatic configuration of the receiver to demultiplex and decode the various streams of programme within the multiplex.