By collision edited tile (CET) I mean it was changed from cannot walk through to being able to walk through it.
Examples are in the sewage treatment and corporate wasteland maps, the tiles at the top of each stairway are CETs, it is half stone/concrete and half brown brick/lattice whatever. Normally a player cannot walk through brick/lattice half of this tile.
If there is an existing map with CETs, it can be loaded into the map editor and the CETs can be copied pasted, redesigning into new map. A map with all different tiles already in it as CETs is a full pallet of tiles not limited to one tile type.
Eedoks samap util will show the different tile types but cannot, as far as I know, change the tile type so it can be walked through.