A drawing database contains two types of non-graphical objects: dictionary and symbol table objects.
Although there are similarities between these object types, they are handled differently. All object types are supported by the entget, entmod, entdel, and entmake functions, although object types individually dictate their participation in these functions and may refuse any or all processing. With respect to AutoCAD built-in objects, the rules apply for symbol tables and for dictionary objects.
All rules and restrictions that apply to graphical objects apply to non-graphical objects as well. Non-graphical objects cannot be passed to the entupd function. When using entmake, the object type determines where the object will reside. For example, if a layer object is passed to entmake, it automatically goes to the layer symbol table. If a graphical object is passed to entmake, it will reside in the current space (model or paper).