Arguing semantics can easily distract from the evidence, and substantially weaken your position.
Do not allow that to happen.
The labels are irrelevant.
Argue directly from the evidence and bypass pointless labeling. Id est, argue from test results, behavior, affect, and so on. If this approach makes people uncomfortable, remind them that these are facts and ask what word they would like you to use instead�strategically, this gives you an opportunity to ask for a favor and thereby make use of the Benjamin Franklin effect, strengthening your position. When thus using a label they have suggested, be quick to remind people of what facts this label stands for if they fail to appreciate this meaning and argue instead from semantics. As the label was chosen to stand for these facts by your �opponents�, your position is further strengthened.
Another effective strategy would be to ascertain that your DS's name is directly associated with these facts. Thus, any mentioning of his name will directly bring to mind his characteristics and situation.
In any event, make also sure that his name or the label that you eventually use (should it come to this) is directly associated with positive affect. This is important because �open-mindedness� is directly linked to positive emotion, whereas negative emotion is linked to �narrow-mindedness� and focusing on the negative. Making sure the association is with positive affect, you avoid association with negative affect. This is admittedly easier said than done. (Sources:
http://journal.frontiersin.org/article/10.3389/fpsyg.2015.00670/full and
http://journal.frontiersin.org/article/10.3389/fnhum.2014.00114/abstract.)
I wish you and your son all the best!
Don't give up, never give up hope!