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: TPO621
name: 18/1986
tree-preservation-order: undefined
18/1986
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.637606 51.292082,0.637501 51.292082,0.637207 51.292118,0.637015 51.291492,0.636844 51.291027,0.636342 51.291120,0.636276 51.291152,0.636278 51.291107,0.636268 51.291082,0.636083 51.290903,0.635924 51.290624,0.635817 51.290335,0.635823 51.290312,0.635867 51.290287,0.635927 51.290271,0.636649 51.290179,0.636708 51.290166,0.636810 51.290159,0.636987 51.290162,0.637479 51.290118,0.637771 51.290047,0.637918 51.290031,0.638087 51.290024,0.638126 51.289984,0.638131 51.289968,0.638179 51.289959,0.638298 51.289954,0.638503 51.289971,0.638901 51.289983,0.638887 51.290021,0.638841 51.290043,0.638798 51.290099,0.638787 51.290160,0.638778 51.290290,0.638821 51.290382,0.638807 51.290448,0.638820 51.290577,0.638812 51.290609,0.638789 51.290639,0.638738 51.290927,0.638768 51.291133,0.638853 51.291246,0.638913 51.291405,0.638909 51.291472,0.638852 51.291697,0.638853 51.291720,0.638893 51.291803,0.638886 51.291811,0.639055 51.291850,0.639121 51.291858,0.638989 51.291896,0.638301 51.292017,0.637606 51.292082)))
point: POINT (0.637643 51.290955)
notes: The Maidstone Borough Council Tree Preservation Order No 18 of 1986 under Section 60 of the Town and Country Planning Act 1971 Woodlands - W6 Mixed Deciduous trees consisting
organisation
entry-date: 1986-08-13
start-date: 1986-07-19
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.