One way of telling if there is an enumeration list for a field is that an ellipsis displays when you mouse over it. For example in the Add New Building screen. Sometimes there's a delay between when you mouse over and when it displays. Could the ellipsis be displayed all the time rather than only when you mouse over it?

Also, if you tab across fields, please display the ellipsis to tell you there's an enumeration list and change it so I can hit enter or something to bring up the options in the enumeration list.