Hi, please restrict "private backyard" mapping to a reasonable amount. Especially do not add amenities to OSM that are only used privately, it does not serve any useful purpose for the general public. Furthermore, when people look for e.g. shelters on the map and find these, they might infer that they can be used publicly. (You could add access=private to these amenities, but I still don't see any purpose in adding them in the first place.)
For a guideline, see https://wiki.openstreetmap.org/wiki/Mapping_private_information