dcapillae
(Daniel Capilla)
9
The building:use=* key is specially handy when the form or original purpose of a building differs from its present use. A service building can be used for multiple purposes by definition. I don’t think additional tagging is necessary in that case.
multi in sporting facilites is used with the sport key and means multi-sports. It is used when the facility is not specific for one sport, but can be used for several not specified sports. (i.e. building=sports_hall + sport=multi)