This file defines if items that cannot be used at the same time, value 0 can be used value 1 cannot be used together.
First column is the list of the ITM file names containing of these items.
2nd column is respectively 1 - to not allow using item with other items from the list or 0 - that allows
In BG1 TotS we have:

2DA V1.0
0
           VALUE
CLCK01     1
CLCK02     1
PLAT02     1
PLAT05     1
PLAT06     1
LEAT02     1
LEAT03     1
LEAT05     1
LEAT07     1
LEAT08     1
CHAN02     1
CHAN03     1
CHAN05     1
CHAN06     1
RING06     1
RING07     1
RING25     1
AMUL14     1
LEAT09     1
CHAN07     1
PLAT08     1