Block in the block! How to get parent "main block". We get (BLOCK_HEADER) of each block separately, and after we get (BLOCK_HEADER) parent, in which the inclusion of "children" (blocks) in Example (.. \ AutoCAD 2006 \ Sample \ Hotel Model.dwg). Maybe we need to know for each block parent or it part of another one? Or as some take only the principal components if they exist and blocks if they are not parents?
