Exposure-Preprocessor-Documentation.md

+The `exposurepreprocessor` handles the restructuring and renaming of the aggregated exposure models, and their merge with other data sources such as EUBSO and TABULA. During this process, several attributes in the input models get renamed and the new names should be kept track of. 
+
+- `TOTAL_REPL_COST`: `TRC`
+- `COST_STRUCTURAL`: `CST`
+- `COST_NONSTRUCTURAL`: `CNO`
+- `COST_CONTENTS`: `CCE`
+- `OCCUPANTS_PER_ASSET`: `OPA`
+- `OCCUPANTS_PER_ASSET_DAY`: `OPD`
+- `OCCUPANTS_PER_ASSET_NIGHT`: `OPN`
+- `OCCUPANTS_PER_ASSET_TRANSIT`: `OPT`
+- `OCCUPANTS_PER_ASSET_AVERAGE`: `OAV`
+- `BUILDINGS`: `BLD`
+- `DWELLINGS`: `DWE`
+- `AREA_PER_BUILDING_SQM`: `MAV`
+- `AREA_PER_DWELLING_SQM`: `MAD`
+- `OCCUPANCY`: `OCC`
+- `OCCUPANCY_TYPE`: `OCT`
+- `BOUNDARY_ID`: `BID`