A few days ago I added support to ModelConverterX to read the additional options like <NoShadow /> or <NoAutogenSuppresion /> from the object placement code in the BGL file. Initially I had some trouble to find out where these options ended up in the binary code, since it was not documented in the otherwise excelent description that Winfried Orthmann made a while ago.
After the latitude, longtide and altitude the description says there is a short that stores if the altitude is AGL or not. But actually this short can store much more than that. It more acts like a set of flags for multiple options. Here is the list of possible flags:
0x01 AltIsAgl 0x02 NoAutogenSuppression 0x04 NoCrash 0x08 NoFog 0x10 NoShadow 0x20 NoZWrite 0x40 NoZTest