Template:Description/doc/confusion caused by use on onArea parameter

There is common problem related to how hints about usage on nodes, ways, areas and relations are shown.

Note that

• Use on multipolygons representing is listed in "area" parameter, so key used on areas and used on multipolygons and not used as other relations will be
  • shown as used on areas
  • shown as not used on areas
• Use on closed ways representing areas is listed in "area" parameter, so key used on areas and not used on ways representing lines
  • shown as used on areas
  • shown as not used on ways