There's still a lot we don't know about Trans-Miss Confederate flags and about the only thing written on them is the three part essay that the late Howard Madaus did for Military Collector & Historian some years ago. More information has come out since then of course.
Trans-Miss CS flags break down into a few categories:
1) First Nationals and variants
2) Modified state flags
3) Flags of a unique pattern
4) modified ANY style battle flags, either square or rectangular
5) Second Nationals and variants
I wish we had more to go on for the blue flags with red St. George's or St. Andrews crosses too. How wide spread was their use?
Greg Biggs