You might find this code helpful as a starting point, and also this for heliports.
That code (and the equivalent for Garmin) puts “aerodromes” into one of three categories:
- Large public airports. Somewhere you would go to catch a commercial flight.
- Military airports.
- Other smaller aerodromes, sometimes referred to as “general aviation” - includes sites used by gliding clubs etc.
No change there, then 
In practice, using taginfo and overpass to look at the usage of particular keys and combinations in certain areas will be far more useful than trying to understand the wiki.