Tell whomever has these opinions to go look in the official DSM 5 . That is where the guildlines for ASD are. The word "high functioning" is subjective to the persons opinion on the subject matter. It is not an actual medical diagnosis. Like they said above it is the old way of labeling people, but there were mainly 3 categories, low, high, or Aspergers. But now they know that people are much more diverse than that... hence the new Spectrum title.

When I use the term HFA to describe my son I generally mean he is at the higher end of the spectrum, I don't use it as a diagnosis. My son is what most would consider high functioning because he is verbal and has a 90+ IQ however his official diagnosis is autism.

In the new standard there is no difference in range anymore you either have autism or you don't so to speak. There is no more PDD-NOS or aspergers anymore. There have always been doctors who do not want to make the autism call so to speak so they would use the other terminology to pick something else. PDD-NOS is a prime example of this. Think about it not otherwise specified what does that mean, would you think of autism with that term. The other issue is that when it comes to insurance they will not pay for a service unless the medical codes determine a specific disability. The schools worker in the same manner, where autism got you services and PDD-NOS did not.

According to the new guide lines or relatively new ones, your right high functioning now longer exists. It use to mean an individuals IQ weighed in mental awareness. Now all that is changing diversity training has started having a impact on the way people in general look at disabilities. They are now more likely to look at the individual ability to interact, awareness and mental acuity. Having said that high function seems awareness vs. relativity to what is going on around the individual. I say this because I have children who fit into both of the old labels of Aspergers and high function.Hope this helps.
Neither should be used you should be emphasizing the inability of the individual to relate to academics or people. That is what you want to address.