Confused about vinegar!

Question

I'm confused about the vinegar situation. On the list you have "Vinegar (when listed alone)" is OK. Then, when I did a board search for vinegar, I found this answer: "we do the research on some items that contain vinegar. There's not enough time in the day to research all. Do not buy an item containing vinegar unless we can verify what vinegar is used. YA" 1) So if a product contains vinegar but is not on the list (ie pickles, salad dressing) can it be used for Pesach or not? 2) If we can't use it on Pesach can it be kept in the house? 3) Would the same apply to "distilled vinegar" when listed as an ingredient? Thank you!!