Let me try to sum it up:
I have read several statements in the OSM space about INSPIRE data. They testify to doubts about whether INSPIRE data can be imported into OSM.
For example, at the link provided by Mateusz, until recently one could read about INSPIRE:
“The data is on licensing rules making it unusable in OSM.”
This has recently been removed. See discussion → Talk:INSPIRE - OpenStreetMap Wiki
Here is another thread testifying to these doubts:
https://community.openstreetmap.org/t/inspire-noconditionsapply-vs-cc-by-4-0/8334
I understand that:
There is no single INSPIRE database. There are many INSPIRE databases run by different institutions in different countries. Perhaps each of these databases is a different case.
Mateusz’ question refers to a specific database with information about heritage objects in Poland:
https://dane.gov.pl/pl/dataset/1130,rejestr-zabytkow-nieruchomych/resource/53559/table?page=1&per_page=20&q=&sort=
The thing is that INSPIRE IDs are practically the only ones that uniquely identify heritage objects in Poland.
But this database is based on a licence: CC BY 4.0
Which means:
I can do practically anything with the data but it is necessary to: “Attribution - You must label the work appropriately, provide a link to the licence and indicate if changes have been made to it. You may do this in any reasonable way, as long as it does not suggest endorsement by the licensor of you or the way you use the work.”
[Such a licence - for a government institution maintained with my taxes seems like an abuse - but that’s another story.]
But:
We only want to take the INSPIRE ID from the database and copy it to ref:inspire
I understand that this does not violate the licence.
As Mateusz wrote: