In a Duolingo discussion I came across, that people understand the word sandviĉo differently. For me the default type is what seems to be called in English open or open-face sandwich, that is one slice with some topping. In some parts of the world the word sandwich refers exclusively to layered bread, i.e. at least two slices with some filling between them. There also seems to be countries, where the word sandwich is reserved for layered breads with some particular filling.
The Esperanto word sandviĉo appears to cover all types of sandwiches. How do you specify the type if necessary? Wikipedia has an article of sensupropana sandviĉo for the open type one, but that name sounds very clumsy (and malferma just strange) to me. Would tavola sandviĉo be understood for a layered, two-sliced sandwich? What other alternatives are there?