I have come across a superbly executed SubRip (.srt) file that seems to use a special markup for words that may be muttered, spoken unclearly, or perhaps that the transcriptor has guessed at.

For instance there is this line

{\Well, } if you make a habit of crashing into other people's homes,


I was the talk of London{\, you know}.

I wonder if anyone has seen this construct before, and if there is a proper definition of how the corresponding subtitle should be rendered?