My adult DD does not understand what the words "additional" or "support" or "needs" mean, because they are all conceptual - never mind all three put together in a particular concept. I also doubt she processes the difference between "she has special needs" or "she is special needs", as its likely all she gets is "she" and "needs". However, what does really bother her is that people stare at her, when she goes out in public.
While I accept that some phrases such as "retard" or "mentally handicapped" are offensive, I find it bizarre that people get so hung up on subtle differences in terms like special needs as opposed to additional needs, when so many children and adults with special/additional needs encounter stigma, public disapproval and lack of understanding from other "normal" people in public. Read countless posts on MN by parents of children with ASD, ADHD or whatever and how upset and depressed they are, because they feel obliged to be seen to be doing something about their child's behaviour at soft play, the park, etc as other parents disapprove and clearly see them as incompetent parents, rather than people struggling to do their best to take their child off to run around and let off steam!
IMO, there is discrimination in the NHS, education, politics (implicitly not explicitly), where the attitude is that children or adults with learning disabilities are second class citizens, and are not worthy of the extra resources, unless their parent/carers fight every step of the way, for every bit of help they get. I would prefer to see more education to teach everybody a bit about common conditions and change attitudes, rather than arguments about what are the latest acceptable labels. The actual terminology used is largely irrelevant imo, to the fundamental attitudes underneath - people can use the most politically correct terms in the world, but still say them sarcastically to express how they really think!