The `area=yes`/`no` tags are supplementary tags for ambiguous situations, and not meant to be used as main tags. For tagging of protected areas the wiki article for their [boundaries][2] and the rather opaque [protect class][3] tags are probably a good starting point. `leisure=nature_reserve` [`leisure=nature_reserve`][4] may be appropriate if there is some degree of access allowed by the public. Mistagging specifically so that the area doesn't render as green is [generally discouraged][5]. [2]: https://wiki.openstreetmap.org/wiki/Tag:boundary%3Dprotected_area [3]: https://wiki.openstreetmap.org/wiki/Key:protect_class [4]: https://wiki.openstreetmap.org/wiki/Tag:leisure%3Dnature_reserve [5]: https://wiki.openstreetmap.org/wiki/Tagging_for_the_renderer

The `area=yes`/`no` tags are supplementary tags for ambiguous situations, and not meant to be used as main tags. For tagging of protected areas the wiki article for their [boundaries][2] and the rather opaque [protect class][3] tags are probably a good starting point. `leisure=nature_reserve` may be appropriate if there is some degree of access allowed by the public. Mistagging specifically so that the area doesn't render as green is [generally discouraged][5]. [2]: https://wiki.openstreetmap.org/wiki/Tag:boundary%3Dprotected_area [3]: https://wiki.openstreetmap.org/wiki/Key:protect_class [4]: https://wiki.openstreetmap.org/wiki/Tag:leisure%3Dnature_reserve [5]: https://wiki.openstreetmap.org/wiki/Tagging_for_the_renderer