It adds a new Weight Paint tool called "Normalize Unlocked".
This tool is similar to the built-in Normalize All, except that it ignores the vertex groups that are locked.
It normalizes weights only between unlocked groups, useful for when you have vertex groups for many uses in the same mesh, like for skinning, hair, modifier influences etc.
This way you can lock all the groups that you don't want to affect.
For keymaps, the operator name is:
For questions or bug reports: