Tree preservation zone

There is a problem

1000 entries with tree-preservation-order field must match the reference field in the tree preservation order dataset

reference: TPO581
name: 1/1975
tree-preservation-order: undefined
1/1975
tree-preservation-zone-type: area
geometry: MULTIPOLYGON (((0.612980 51.285157,0.612905 51.285032,0.612969 51.284992,0.613008 51.285072,0.613077 51.285162,0.613119 51.285243,0.613211 51.285381,0.613332 51.285501,0.613792 51.285917,0.613965 51.286128,0.614013 51.286230,0.614117 51.286366,0.614162 51.286447,0.614173 51.286525,0.614321 51.286786,0.614416 51.286913,0.614482 51.286979,0.614611 51.287074,0.614653 51.287114,0.614672 51.287155,0.614581 51.287191,0.614324 51.286913,0.614157 51.286651,0.614103 51.286532,0.613877 51.286135,0.613825 51.286058,0.613773 51.285999,0.613193 51.285433,0.613061 51.285288,0.612980 51.285157)))
point: POINT (0.613842 51.286148)
notes: County of Kent (Maidstone Borough) Tree Peservation Order No. 1 of 1975 under Section 60 of the Town and Country Planning Act 1971. Area of Trees - A9 The several Ash, Cherry, Plum,
organisation
entry-date: 1975-10-29
start-date: 1975-09-30
end-date

Your dataset is missing the tree-preservation-order column.

The Tree preservation zone guidance explains how to fix the issue:

The reference for the tree preservation order that covers this zone.