The Timed Text Working Group has published TTML Profiles for Internet Media Subtitles and Captions 1.0.1 (IMSC1) as a W3C Recommendation. This document specifies two profiles of [TTML1]: a text-only profile and an image-only profile. These profiles are intended to be used across subtitle and caption delivery applications worldwide, thereby simplifying interoperability, consistent rendering and conversion to other subtitling and captioning formats. It is feasible to create documents that simultaneously conform to both [ttml10-sdp-us] and the text-only profile. The document defines extensions to [TTML1], as well as incorporates extensions specified in [ST2052-1] and [EBU-TT-D]. Both profiles are based on [SUBM].