Communication requires thought and input from both sides - if I use a numeric abbreviation with someone who is unfamiliar with it, I am communicating badly. I

Communication requires thought and input from both sides - if I use a numeric abbreviation with someone who is unfamiliar with it, I am communicating badly. I think where we differ is that I see such abbreviations as no worse than any other - TLAs (three letter acronyms) can also be as impenetrable.