What Not to Bring to a Potluck

My mom loves hosting people at her house and sometimes I'll help her. I'm always baffled by the cluelessness of some of her guests.
  1. Anything that needs to be frozen: ice cream, Popsicles, etc
    Don't assume you have access to the host's freezer because there's a chance the freezer is full and your "dish" will melt
  2. Half-prepared dishes
    Don't assume you have access to the host's kitchen. The host may need it or does not have time to show you where everything is stored
  3. Cheap junk: chips, pretzels, soda
    The host will have them and it's lame to show up with some things you grabbed in the snack aisle while everyone else spent time on their dishes
  4. Pizza
    If the host wanted to have a pizza party, then it would be a pizza party and not a potluck. Again, don't assume you have access to the host's oven to reheat
  5. Expensive but small dishes
    You may feel generous for bringing a delicacy but it's awkward when there's not enough to share
  6. Open bottles of alcohol
    Suggested by   @aus10
  7. Bottles of red wine- just not considerate!
    Suggested by   @TheJuliaBeck
  8. Intimidation.
    Suggested by   @eriknmichaelssrn