[Mobhack]

Game Guide, Map Editing Hot Keys link.
Read the descriptions of these till you find your answer.
NB - the description of the key you are seeking reads "lock the current building type until you press another icon or button. Very useful in laying city grids!"

Or if in the scenario map editor, press the "help" button. The section you require is on page No. 1 of the help text entitled "Map Editing Basic Help". It is the section entitled "Hot keys for map editing". Your answer appears on page 2.

(If you have not come across the Game Guide as yet, please see the sticky post at the top of the main forum entitled "where to find help", point #1, accessing the in-game help text system is described in point #2 of that post)


Andy