I've seen this image...



...in the "Forced Sub" tutorial on the Doom9.org site, but no mention is made of the syntax of the "forced" flag in the IDX file that causes the "Yes" to appear in this column.

Unfortunately, the only forced sub discs in my collection are the second type listed in the tutorial (where "forced subtitles are placed in another subtitle stream"). Can someone share with me exactly how to flag an individual sub to be "forced"? Thanks!