This can be a tricky question, because it often turns on whether the public is likely to actually be confused.

In one recent case, a California company called White Oak Vineyard & Winery brought a lawsuit against a Florida vodka distiller called White Oak Spirits.

The vodka company argued that wine and vodka are different products, and that no one would be confused by the two names, especially since White Oak Vineyard was not a nationally known brand.

But a California federal judge sided with the winery, and said the two alcoholic products were similar enough that consumers might be confused as to whether they were related.