Property to tag public domain-compatible sources

[quincylvania]

Hi folks! Over at OpenStreetMap US we've recently started piloting our Public Domain Map tool. PDMap is an interim database based on the OSM tech stack, but with a more permissive license. It allows groups that are limited to public domain-licensed data, such as US government agencies, to setup open mapping tasks via the OSM US Tasking Manager. Once data is mapped and validated, it will become available as an OSM data source.

Public Domain Map uses a fork of the iD editor that relies on 100% public domain-compatible data sources. We'd love to integrate the editor-layer-index and simply filter out any non-PD sources, but there's currently no machine-readable property indicating PD compatibility. I propose adding a property such as this:

"pd_compatible": {
    "description": "Whether data derived from this source is compatible with a public-domain-equivalent license",
    "type": "boolean"
}

Existing consumers can simply ignore this flag. Note that the imagery itself needn't be in the public domain so long as the license indicates compatibility for derived data.