Bosnia's constitution does not specify any official languages. However, academics Hilary Footitt and Michael Kelly note the Dayton Agreement states it is "done in Bosnian, Croatian, English and Serbian", and they describe this as the "de facto recognition of three official languages" at the state level. The equal status of Bosnian, Serbian and Croatian was verified by the Constitutional Court in 2000. It ruled the provisions of the Federation and Republika Srpska constitutions on language were incompatible with the state constitution, since they only recognised Bosnian and Croatian (in the case of the Federation) and Serbian (in the case of Republika Srpska) as official languages at the entity level. As a result, the wording of the entity constitutions was changed and all three languages were made official in both entities. The three standard languages are fully mutually intelligible and are known collectively under the appellation of Serbo-Croatian, despite this term not being formally recognized in the country. Use of one of the three languages has become a marker of ethnic identity. Michael Kelly and Catherine Baker argue: "The three official languages of today's Bosnian state...represent the symbolic assertion of national identity over the pragmatism of mutual intelligibility".