2012-02-15 13:21:26: Created issue 'Centered flush left captions' nickname Centered flush left captions owned by Sean Hayes on product DFXP v.next, description 'In common captioning practice it is often required to position each caption horizontally (often centered), while retaining flush left justification of the text.
While it is technically possible to do this in TTML 1.0 e.g. using a named region for each <p> element, or a sequence of <set> elements, it is verbose, and also complex to generate this on the fly (e.g. from a 608 source file).
Furthermore since regions can only be positioned from the top left edge, positioning such regions requires explicit knowledge of their width (which is content dependant).
In CSS, the margin feature allows this kind of positioning, this should be added. Consider whether margins should be added, as well as some kind of content dependant width value.' non-public [Sean Hayes]