Proper Limb Cutting Technique
Provided by  Rob Horton of Crestline, CA.
Certified Arborist and Professional Tree Trimmer
Example of limb tear due to upper cut removal of limb without using stop cut  
technique
Removing a limb safely without causing damage to tree:

1.  Undercut limb to provide a "stop cut".

2.  Direct cut to top of limb showing tear to bark stopped by
undercut.

3.  Removal of limb stump in safe manner near collar.