The drawing interchange format (DXF) file type, developed by AutoCAD, has been in use for many years and is accepted by almost all computer-aided drafting (CAD) systems. It is in ASCII format, and can be viewed on text editors.
The DWG format is a more compact binary format used in AutoCAD, and adopted by other CAD programs such as BricsCAD. DWG files can be converted into DXF files for entry into DRAINS, with older file versions being preferred.
In AutoCAD these formats change with different versions, and considerable new material is added with each annual change of version. For this reason, DRAINS only accepts DXF files when importing backgrounds and pit and pipe locations. This simplifies transfers and makes it possible to transfer arcs as well as lines and poly-lines from the background layer.