In Hong Kong, this refers to:
- Old & Valuable Trees confirmed with Brown Root Rot disease infection
- Mature trees with individual trunk(s) over 750 mm DBH / OVTs / stonewall trees with crown spread within dripline of confirmed BRR infected tree
- Mature trees with individual trunk(s) over 750 mm DBH / OVTs / stonewall trees having one or more of the following major structural defects or health problems:
- (i) Open cavity on trunk having the longest axis ≧1/3 trunk diameter
- (ii) Co-dominant trunk with included bark / decay / cavity / split in the union
- (iii) Decay / damage with more than 120 degree in the root flare
- (iv) Over 20% die-back of crown
- (v) Presence of wood decay fungi at trunk and/or root zone within dripline