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 BG2EE we have:

2DA V1.0
0
          VALUE
AMUL14    1
BDAMUL24  1
BDAMUL25  1
BDCHAN01  1
BDCHAN02  1
BDCHAN04  1
BDCHAN05  1
BDCHAN06  1
BDCHANCA  1
BDLEAT01  1
BDLEAT02  1
BDLEAT03  1
BDLEAT04  1
BDLEAT06  1
BDLEAT07  1
BDLEAT08  1
BDPLAT01  1
BDPLAT03  1
BDRING06  1
BDRING07  1
bruenpla  1
CHAN02    1
CHAN03    1
CHAN05    1
CHAN06    1
CHAN07    1
CHAN08    1
CHAN09    1
CHAN10    1
CHAN11    1
CHAN13    1
CHAN14    1
CHAN15    1
CHAN16    1
CHAN17    1
CHAN18    1
CHAN19    1
CHAN20    1
CHAN21    1
CLCK01    1
CLCK02    1
CLCK31    1
DWCHAN01  1
DWCHAN02  1
DWPLAT01  1
LEAT02    1
LEAT03    1
LEAT05    1
LEAT06    1
leat06    1
LEAT07    1
LEAT08    1
LEAT09    1
LEAT11    1
LEAT12    1
LEAT13    1
LEAT14    1
LEAT15    1
LEAT16    1
LEAT17    1
LEAT18    1
LEAT19    1
LEAT20    1
LEAT21    1
LEAT23    1
LEAT24    1
LEAT25    1
NPCHAN    1
NPPLAT    1
OHCHAN50  1
OHDARMOR  1
OHLEAT50  1
OHLEAT51  1
OHLEAT52  1
ohnamul2  1
OHPLAT50  1
PLAT02    1
PLAT05    1
PLAT08    1
PLAT10    1
PLAT11    1
PLAT12    1
PLAT13    1
PLAT14    1
PLAT15    1
PLAT16    1
PLAT17    1
PLAT18    1
PLAT19    1
PLAT20    1
PLAT21    1
PLAT22    1
PLAT23    1
PLAT24    1
RING06    1
RING07    1
RING25    1
RING41    1
WA2PLAT   1