The inventory of Houthulst was done in great details: a map of the municipality with the World War remains drawn on it.

In February 2004 a new C.A.I.-project started with the goal of making an inventory of all World War One remains in Western Flanders, based on Wartime aerial photographs. At first, a basic inventory will be made of all the frontlines and defensive lines. The most seriously threatened areas, are also inserted in the inventory in a very detailed manner. The computer recalculates the wartime aerial photographs to fit on a contemporary map according to a number of indicated points; this technique is called image warping. Next, polygons, lines or dots on the modern map can indicate the structures visible on the aerial photograph. Meanwhile, in the area through which the A19 could be extended the inventory of the structures will continue in a very detailed manner, also using aerial photographs.
Parts of the Hollandstellung and remains of World War 1-heritage in several villages have been the subject of an extensive inventory, the C.A.I. (Central Archaeological Inventory), since 2001. Taking inventory of this heritage (consisting of trenches, metre gauge railways, (deep) dugouts, concrete shelters, etc.) and placing it in proper archaeological and historical context was not an easy task. Therefore the study of the so-called trenchmaps and aerial photography from the Great War were an important source of information with which to begin the field work itself.