I'm not sure what the difference is in acidity between the various Vinegars, they tend to be either 5% or 6%. At 5%, they would contain 13.85g of Acetic Acid per cup [0.86g per Tbsp.] At 6%, they'd have 16.62g of Acetic Acid per cup [1.0g per Tbsp] give or take a tenth or two. Anything over and above that may be true carbs. For example, 2-3g of Carbs ~ 6% Acidity for Balasamic Vinegar means that 1-2g of the 2-3g is not Acetic Acid, and is therefore Sugar.

There may be a trace of Carbs in Apple Cider or Red Wine Vinegars, since these are distilled from foods that contain Carbs, while White Vinegar is distilled from 196 proof Alcohol, which should have no Carbs [unless a trace was left over from the inital distillation of the Alcohol.] but if there is it would only be a very, very small amount...The Carbs are supposed to be completely converted to Acetic Acid [Vinegar.] The Acetic Acid is diluted to either 5% or 6% Acidity with Water.

Vinegar is a cool example of converting macronutrients from one type to another. It goes from Sugar --> Alcohol --> Saturated Fat.