Topic-prominent languages organize sentences to emphasize their topic–comment structure. Nonetheless, there is often a preferred order; in Latin and Turkish, SOV is the most frequent outside of poetry, and in Finnish SVO is both the most frequent and obligatory when case marking fails to disambiguate argument roles. Just as languages may have different word orders in different contexts, so may they have both fixed and free word orders. For example, Russian has a relatively fixed SVO word order in transitive clauses, but a much freer SV / VS order in intransitive clauses. Cases like this can be addressed by encoding transitive and intransitive clauses separately, with the symbol "S" being restricted to the argument of an intransitive clause, and "A" for the actor/agent of a transitive clause. ("O" for object may be replaced with "P" for "patient" as well.) Thus, Russian is fixed AVO but flexible SV/VS. In such an approach, the description of word order extends more easily to languages that do not meet the criteria in the preceding section. For example, Mayan languages have been described with the rather uncommon VOS word order. However, they are ergative–absolutive languages, and the more specific word order is intransitive VS, transitive VOA, where the S and O arguments both trigger the same type of agreement on the verb. Indeed, many languages that some thought had a VOS word order turn out to be ergative like Mayan.