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Mar 04, 2011


Evan Yares

Filename extensions don't actually include a period. The period is a separator. So, when you're referring to the DWG filename extension, you don't need to include the period.

Also, tracing the history of the DWG filename extension, it was originally upper case. Today, it's actually case insensitive. It's probably more proper to write the DWG filename extension as "DWG". (Just as with the PDF filename extension.)

So, you have the DWG mark, on one hand, and, on the other hand, the DWG filename extension, which is used on DWG files to identify the DWG format.

Seems perfectly clear, doesn't it?

Owen Wengerd

The comparison to PDF is a good one, and the point you make is essentially the examining attorney's argument against allowing the registration. However if registration eventually succeeds, competitors will refer to them as .dwg files to avoid infringement claims.

Evan Yares

Even Autodesk doesn't refer to them as .dwg files with any consistency.

Ralph Grabowski

I used DWG when describing the format ("DWG format") and .dwg for the file (".dwg files" or "drawing.dwg").

The period indicates I am referring to a file extension. The use of lowercase goes back to when Autodesk rewrote its documentation to allow for Unix versions of AutoCAD.

Unix is case-sensitive, wjhereas DOS (and now Windows) isn't. For compatibility, all file names needed to be in lowercase. To distinguish filenames from the rest of the documentation text, Autodesk wrote them in italics -- a practice I continue to use.

Quoting from the "AutoCAD Reference Manual" for Release 12,

"If you expect to transfer files between UNIX and other systems, we recommend that you enter all filenames in lowercase..."

That would apply to drive and path names, as well.

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