SRT (SubRip Text)
A subtitle format supported by Facebook, YouTube, and Vimeo. The SRT format is simple: Each caption has a number, a start and end timecode (in decimal timecode), and one or more lines of text. SRT captions can be imported or exported as separate files. Unlike captions in other formats, exported SRT captions can be read and edited in a plain text editor. SRT caption files have the filename extension .srt.