No, I think he means like the way attributes work in AutoCAD, for example, you create an editable attribute which prompts you for the design engineers name, so as you insert the symbol into your drawing, a little box will pop up asking you to fill in a field for the responsible design engineers name. You can also have a place holder, so if you insert the symbol and cancell the input dialog box, the attribute will just display a hyphen maybe, if thats what you have chosen as your place holder, until the time comes when you can just double click the symbol and the input dialog box will come up.
I would also be interested if this is possible for all out custom symbols that require user input upon placement.