The present document specifies the transport of TTML [2] subtitle streams in DVB MPEG-2 transport streams, based on the MPEG-2 system described in ISO/IEC 13818-1 [1]. TTML is an XML-based representation. The present document provides syntax for delivery of TTML subtitle streams over MPEG-2 transport stream, and is based on EBU-TT-D [3] compatible with the IMSC1 [4] Text Profile of W3C TTML [2].