My BD player doesn't provide that information and it wasn't printed in any of the press materials or packaging. But looking at other reviews, it's AVC for First Blood and VC-1 for the sequels.
What do you mean by "unadvertised audio track accompanies the trivia track"? Does this mean I can't listen to the audio commentary and have the trivia track running at the same time? Most discs allow for this and I'm hoping this can be done here.
You can listen to the commentary and have the trivia track going at the same time - sorry if that isn't clear. However when you select the trivia feature off the menu it will automatically select the audio track with the pop up sound effects unless you select a different audio track, either through the player as you're watching the feature or through the BD menu. Just be sure you select the trivia feature first or it will override your initial audio selection. The trivia is just another subtitle track as it is usually done.
What's the sitution with the Russian/English subtitles? Did they get it right AT LAST?
1. Are there (correctly) just a handful of lines translated/subtitled (as per the theatrical run and the very first DVD) or... 2. Have the translations been left out altogether (as per the second DVD) or... 3. Have they incorrectly subtitled literally EVERY LINE of Russian into English such as "Quiet Quiet", "Run Run" and other such crap as per the so-called "Ultimate Edition" DVD?
I looked at the scene where Rambo first sneaks into the fort and all the Soviet guards have been translated. We get things like, "Relax, Rex. Relax, Rex." and "Go drag that box." So it looks like #3 from your list.