Tax help for military filers

I am not totally understanding this topic.  Am I right that Military retirement pay is 100% taxable even though you may be receiving disability pay (over 30% disabled) from the VA.

I am being told that since I am honorably retired and I am also disabled then I should not being taxed on my Military Retiree pay at 100%.  The scenario being floated is that if you are 80% disabled then only 20% of your Military retirement pay should be taxed.

Can you help me understand this?