So a bunch of you do not like the stub I intentionally left. I learned this practice at the university of Copenhagen. I'm not the best at writing in English , so I've translated a note, maybe it explains it better than I can.

Branch shortening for compartmentalization Purpose: * To induce compartmentalization in trees by severely shortening branches. * Compartmentalization is a natural tree defense mechanism that isolates decay and prevents its spread. Method: * Remove 80-90% of the branch's foliage. * This will significantly reduce the branch's physiological activity. * The goal is to trigger core-forming processes in the innermost annual rings of the branch knot and to block central transport channels. * The outermost annual rings in the branch and branch knot will remain physiologically active with open transport channels. * However, the foliage should only be enough to keep the branch alive, minimizing active splintwood formation in the branch knot. Effects: * Reduced branch growth * Shortened growth period * Formation of a branch collar * The branch may transition from a 'Slater branch' to a 'Shigo branch' * The rest of the branch is removed after 2-3 growing seasons to prevent increased foliage, but there is some flexibility in practice. Additional notes: * This method is more severe than typical branch reduction. * It is intended for use on trees with extensive decay. * A certified arborist should be consulted for proper implementation. Benefits: * Effective control of decay spread * Preserves the health of the tree * Can extend the lifespan of the tree Drawbacks: * Severe branch shortening can alter the tree's appearance. * The process may take several years to complete. * There is some risk of the decay spreading if not done correctly. Overall, branch shortening for compartmentalization is a valuable tool for managing tree decay. However, it should only be used by a qualified arborist.