DXF Group Codes General DXF Conventions

Object and Entity Codes

In the DXF format, the definition of objects differs from entities: objects have no graphical representation and entities do. For example, dictionaries are objects not entities. Entities are also referred to as graphical objects while objects are referred to as nongraphical objects.

Entities appear in both the BLOCK and ENTITIES sections of the DXF file. The appearance of entities in the two sections is identical.

Some group codes that define an entity always appear; others are optional and appear only if their values differ from the defaults.

Programs that read DXF files should not assume that the groups describing an entity occur in the order given here. The end of an entity is indicated by the next 0 group, which begins the next entity or indicates the end of the section.

Note  Accommodating DXF files from future releases of AutoCAD will be easier if you write your DXF processing program in a table-driven way, ignore undefined group codes, and make no assumptions about the order of group codes in an entity. As AutoCAD is further enhanced, new group codes will be added to entities to accommodate additional features.