AutoCompleteTextView how to make reverse option, show words that are taken?

Question

Java

Kind
I suppose AutoCompleteTextView can approach for my task. The bottom line is that you need to force the user to use unique names. I see in the variant that when you enter, a list of busy names pops up (by analogy with the search for a match). There are many names, there should not be any coincidences, spaces / commas / periods do not count, only words, you can add numbers to the cut. Those. Words that fall out of the list cannot be selected. Another question, the subd is multilingual, is it possible to make a list of excluded characters, like "!", "?" ?