If a recipe doesn't specify the type of vinegar, is there a standard type implied? I occasionally come across recipes that call for vinegar, but don't specify which of the many varieties they mean. (A recent example is this recipe for a corn and pepper salad, which just says "2 tbsp. vinegar".)

While I recognize that sometimes this may just be that the recipe is badly written, I've encountered it often enough to wonder: is there a "standard" or implied type of vinegar that should be used when a recipe simply calls for vinegar? Or is it assumed that the chef will be familiar with the flavor profiles of the dish they are trying to make and will be able to choose an appropriate vinegar by their own knowledge and discretion?

I've been unable to find an authoritative answer to this: other forums provide conflicting answers with no documentation or reasoning for the answer put forth, or make it seem like your only options are white vinegar and cider vinegar.
If a recipe asks for "vinegar", a standard type is implied, namely white vinegar.
There certainly are more vinegars than just the white and the cider one (white wine or balsamic are also often used).

However, cultural differences can play a role. I've found on wikipedia that English people put malt vinegar on their fish 'n' chips. If you would see a recipe for fish 'n' chips that calls for "vinegar", my guess is that malt vinegar is meant. I'm sure there are other cultures which use other vinegars as standard. You can always ask some people in your environment. If they all agree, you can assume that's your standard vinegar.