Hop stand Vs 0 min boil

The whole point of a "hop stand" is that below a certain temperature (around 80°C), theoretically very-little/zero bitterness will be extracted from the hops.

This process step came about with large brewing equipment, where the wort can remain hot during the possibly lengthy lautering process (where spent grain is removed from wort). Thus a large "zero minute" addition, supposedly for aroma only, would sit in the hot wort, contributing some bitterness.

Thus waiting for the wort to cool below the hop alpha-acid isomerisation temperature, then adding aroma hops (theoretically) results in no increased bitterness. (Hop alpha-acids, which contribute bitterness, do not readily dissolve into wort unless isomerised).

If you want to experiment with a hop stand, in lieu of having a specific temperature (as @brewchez states), wait until the wort is below 80°C before adding them. Or just put them in at end-of-boil, and don't worry about it.

It depends on how clearly the recipe was written. Typically a zero minute addition means adding hops directly at flame out and then the wort chilling begins. A hop stand would typically mean hops are added, usually post boil, and allowed to sit for a defined time and/or a defined temperature. An example of a hop stand would be "cool wort to 140F, add hops and let stand for 15minutes".

If there is no good designation about the stand then I'd have to assume that the recipe originator doesn't understand the difference either.

Either way zero minute additions and hop standing is intended to add aroma to the beer. We all need to remember that recipes aren't the sole driver of a great beer. Its mostly process. Knowing that when I see zero minute or hop stands in a recipe I tend to apply my own preferred process for driving aroma when the specifics are not called out in the recipe.