I just want to precise that I don't confuse forum and technical support. The sense of my intervention is to share experiences or to allow others users to find response to their own interrogations. I'm sorry if my words aren't always understandable. It is a question about the table shown in FZ's Manual's user, Volume 1, seventh edition, march 2000, section 3.13.6, page 3-237. This table summarizes the Autocad entity types supported by FZ's DWG translator.
Splines are lines after they are created and it's good too.
So I think reality is better than manual's indications. But my question was a little different. That I want to do is to trim with a polyline in fact, exactly with just a polyline's segment. I think it is not a good way. On the other hand your suggestions for changing diameter with parallel tool, and for hatching a polygon with white color are very helpful.