Dash usage for document version

Thanks for the invitation to the forum!

I am an engineer, and technical documents are often revised and formally released into configuration control several times. Subsequent versions are often designated as Revision A, B, C… or 1, 2, 3…. However, the first version is often called “Revision Dash” since it has not been revised yet.

Aside from trying to get engineers to consider the wisdom of dropping the “rev dash” silliness in the first place, what kind of dash is appropriate? I have been using an en dash, but haven’t found any guidance one way or the other.

(For what it’s worth, other engineers tend to use either a hyphen—or an accidental en dash created automatically by Microsoft Word when a hyphen is placed between two words with a space on either side. I am fairly sure I’m the only engineer in my building who has read Practical Typography.)

So you are looking to set a placeholder for the revision number. Clearly a hyphen would not be appropriate there. But then, if you have the choice, why not simply replace the whole text with something like “Initial Version”?

The em dash is longest, and would probably make the best visual connotation of “nothing”. That is a peculiar convention, however.