I am by no means an expert, but I believe it means that it was the first version of that model. A dash was added when there was a major change to the production design of the model.

So a no dash is the very first version and many models like the model 10 have a bunch of dash changes. So if you look at the crane stamp it will give you the model and the dash if there is one. 66, 66-1, 66-2. etc.

A good question and I don't think you will get roughed up on this board for asking newbie questions. You can use the forum thread tools to help you with some of the terminology questions too.

Randy Reinhardt