3D autoswitching mode flag?
 

I've spent quite a bit of time trying to find some info on this and am coming up empty.
The Panasonic HDC-SDT750 camcorder produces simple frame compatible sbs format that when played from a simple SD card autoswitches the 3DTV into the proper mode automatically.
It would be highly desirable to be able to insert this data into my 3D videos but I can't find any info on how to do this.
Any ideas?

I do not know any details in this case, but I would guess it depends on the file format. A file can contain the information of which portions of it are in 3D and which in 2D, and if so, a compatible player can fetch that information from the file.

That said, most video file formats currently in use have been created before 3D became so widely popular, so they would not contain such information. All they know is how to store and retrieve video data without knowing whether it is 2D or 3D.

This is unlike audio files (or audio sections of the video files) which can clearly tell stereo from mono because stereo was already in common use before computers became the tool of editing audio (let alone video).

It is only a matter of time before various old file formats catch up (MPEG is an example of an older format which has added support for 3D). And hopefully any new video file formats will store that information.

If it is an HDMI device, such information is avilable in the HDMI 1.4 and 1.4a specs. I am not sure how public these details are. The industry is working on some of the enhancements to these, e.g. how to handle closed caption, but the basic definitions as you described are there.