AutoCAD’s magic vanishing attachments

There are now quite a few file types that you can attach to an AutoCAD drawing as a reference, in the same way that you can attach other drawings as xrefs. We’ve been able to attach other drawings since Release 11 (1990) and images since Release 14 (1997), but every release since 2007 has introduced a new kind of attachment. In AutoCAD 2010, you can now also attach PDFs, MicroStation DGNs (v7 and v8), DWF and DWFx files. But should you? Maybe not. It depends who is going to use those drawings after you. If you know for certain that …