The target follows the environment
A heated interior and an application facing an exterior façade do not share an equilibrium moisture content. There is therefore no single value that counts as “well dried”; the right value depends on the end use.
If you do not know the target, writing where the piece will be used is enough — the technical office sets it from that and records it per batch.
Over-drying is also a mistake
Going well below the target makes the material draw moisture from its surroundings and swell after delivery. This shows up as dimensional drift at joints and in tongue-and-groove profiles.
The aim is not the lowest moisture but the value closest to the working environment.
Conditioning after delivery
Left in the environment where it will be used, the material closes the remaining gap by itself. In tongue-and-groove profiles and panel work in particular, this wait lowers the risk of gapping and binding after installation.
During conditioning the material should be stacked so air can move through it, and the pallet should not sit directly against the floor or a wall.
Moisture is recorded
Material is dried to the target moisture in a vacuum or conventional kiln and the value reached is recorded per batch, alongside dimensional and surface control before dispatch.
That record lets you trace the value the material left at, should a question arise later.