Aircrafts often deiced on airports in special places.
In Stuttgart Airport (OpenAirportMap: EDDS) these are called de-icing pads. I haven’t found anything how to tag them, so I went with aeroway=deicing_pad.
Do you have any suggestions about this tagging?
Rarely mapped so far, I found this Search results | OpenStreetMap Taginfo on TagInfo. When using these values you might want to map it similar to Tag:aeroway=parking_position - OpenStreetMap Wiki. On some airports even designated parking positions are used for deicing during the cold season, thus serving more than one purpose.
I think it’s a really good idea to use aeroway=parking_position and parking_position=deicing together with ref=DP1 (e.g.). The question is if it really is a parking position in an aviation context of if parking positions in this context are used differently.
In Leipzig/Halle Airport (OpenAirportMap: EDDP) for example there are deicing-pads on a taxiway.
As far as I remember (from having flown to STR regularly) those are only used for deicing. While deicing is active, traffic is routed differently as those positions are normally involved in Twys N and S traffic flow.
Concerning the Leipzig example: this is the nicest and most advanced deicing variant, resulting in short waiting times before departure → helping with hold over times. This is used on bigger modern airports (e.g. MUC as well) and definitely not used for parking 
.
I guess then my suggestion to have a merged tagging like aeroway=parking=position and parking_position=deicing is probably not ideal and we should have a separate tag like aeroway=deicing.
At Munich Airport (OpenAirportMap: EDDM) the deicing areas are tagged as aeroway=apron which is surely not ideal. Furthermore in Munich the facility is called deicing area opposed to deicing pad in Stuttgart.
I was under the impression that an apron was a structural safe parking area for planes. No knowledge much about airports I would assume that a deicing station would require one.
I would favour a dedicated tag for deicing as well.
The areas close to the runway are usually outside the responsibility of apron control, but rather managed by air traffic control and not used for parking.
Based on the map it seems like like there should be deicing area. It could be treated as a landuse representing the responsible. That area can contain the actual deicing equipment.
I’d probably stick to aeroway=* tagging instead of landuse as this is very aviation specific. The yellow highlighting on the above map is not representing anything on the ground. The actual deicing positions are marked on the ground though and there is also guidance via signs to these points.
About the equipment: that is mobile equipment (deicing vehicles) most of the time, static deicing equipment exists, but that’s rather seldom.
