[_tom_]

The distinction is a good one, but the word "engineer" has a long history and varied uses. The guy who runs a train is an "engineer", is he licensed? (maybe he is).

It would be better to create a specific term, like "registered professional engineer (RPE)" that is unique, rather than trying to limit the usage of a common word. This is what I think most places do.

[rubyist5eva]

There is a term, it's "Professional Engineer" or P. Eng. Someone who is a "locomotive engineer" must also be licensed but I think the exception in terms of vocabulary is historical rather than practical.

The word may be "common" but it is also regulated and defined in law.