https://cs.wikipedia.org/wiki/%C5%A0ablona:Pam%C3%A1tky_v_%C4%8Cesku

Památkou_do = a date when the protection ended officially (for former monuments)
Zdroj souřadnic = source of the coordinates, "PK" value used for the "Památkový katalog"
Zdroj souřadnic datum přístupu = access date when the coordinates were taken from the source

Thanks.

I'll do a patch later but adding the following to fields should do it.

{
    "dest": "monument_until",
    "source": "Památkou_do"
},
{
    "dest": "coord_source",
    "source": "Zdroj souřadnic"
},
{
    "dest": "coord_source_date",
    "source": "Zdroj souřadnic datum přístupu"
}

I like how the oposite of "od" is "do" :)

Change 449134 had a related patch set uploaded (by Lokal Profil; owner: Lokal Profil):
[labs/tools/heritage@master] Add known cz_cs fields

https://gerrit.wikimedia.org/r/449134

Change 449134 merged by jenkins-bot:
[labs/tools/heritage@master] Add known cz_cs fields

https://gerrit.wikimedia.org/r/449134

Mentioned in SAL (#wikimedia-cloud) [2018-07-31T09:12:50Z] <Lokal_Profil> Deploy latest from Git master: a230a6e (T200337), 12f5559, bad6d8d (T200410), 3c7e8d9, e00f1b3, a021cb9 (T200428), 0631408, d2e8246, b9ff533, a471c38, 1c5b9f6 [correction to previous]

Should be solved with the next harvest.

No unknown fields anymore :) commons.wikimedia.org/wiki/Special:Diff/313223708