HP-41 module files

[hth]

Looking at the MODFile.h file for the format, I get a bit puzzled by
the two combinations ODD/EVEN and UPPER/LOWER.

Judgning from the comment it seems that a page group of ODD/EVEN does
not impose that any page need to be together in any way?

How does UPPER/LOWER work? They seem to be placed next to each other,
but what happens if there are more than two pages?

To me it seems that it is not really possible to specify a traditional
8K module with these. ODD/EVEN does not that the pages should be next
to each other, and LOWER/UPPER does not impose that they should be
allocated in the same pair 8/9, A/B, C/D or E/F.
What do I misunderstand?

/* relative position codes- do not mix these in a group except ODD/EVEN and UPPER/LOWER */
/* ODD/EVEN, UPPER/LOWER can only place ROMS in 16K blocks */
#define POSITION_MIN 0x1f /* minimum POSITION_ define value */
#define POSITION_ANY 0x1f /* position in any port page (8-F) */
#define POSITION_LOWER 0x2f /* position in lower port page relative to any upper image(s) (8-F) */
#define POSITION_UPPER 0x3f /* position in upper port page */
#define POSITION_EVEN 0x4f /* position in any even port page (8,A,C,E) */
#define POSITION_ODD 0x5f /* position in any odd port page (9,B,D,F) */
#define POSITION_ORDERED 0x6f /* position sequentially in order of MOD file loading, one image per page regardless of bank */

Also, what is the point of POSITION_ORDERED? Flatten out banks? How is
that useful?