Herman’s Delicatessen on Geary Street in San Francisco featured what I, and many of the locals, considered to be the world’s best potato salad.   It was a basic recipe of potatoes, carrots, mayo (Best Foods of course), parsley and vinegar.  It had a silky consistency to it, very thin slices of potato, and was very white in color, as it did not contain any mustard or eggs.  No celery, no onions, no pickles, no pickle juice either.