Turco-Albanian (Τουρκαλβανοί, Tourk-alvanoi) is an ethnographic, religious, and derogatory term used by Greeks for Muslim Albanians from 1715 and thereafter. In a broader sense, the term included both Muslim Albanian and Turkish political and military elites of the Ottoman administration in the Balkans. The term is derived from an identification of Muslims with Ottomans and/or Turks, due to the Ottoman Empire's administrative millet system of classifying peoples according to religion, where the Muslim millet played the leading role. From the middle of the nineteenth century, the term Turk and from the late nineteenth century onwards, the derivative term Turco-Albanian has been used as a pejorative term, phrase and or expression for Muslim Albanian individuals and communities. The term has also been noted to be unclear, ideologically and sentimentally charged, and an imperialist and racialist expression. Albanians have expressed derision and disassociation toward the terms Turk and its derivative form Turco-Albanian regarding the usage of those terms in reference to them. It has been reported that at the end of the 20th century some Christian Albanians still used the term "Turk" to refer to Muslim Albanians. The term Turco-Albanian is a compound made up of the words Turk and Albanian. The word Albanian was and still is a term used as an ethnonym. Whereas the word Turk was viewed at times by Western Europeans or by non Muslim Balkan peoples as being synonymous with Muslim. A study of a collection of Albanian folk songs, published in 1870s by Thimi Mitko, suggests that most Albanian speakers of his time identified themselves and each other through various terms and not a single national designation. Among other terms, Muslims were identified as turq or turkollarë ("Turks"). Apart from being associated with Muslim Albanians, in some specific works the term Turco-Albanian was used to mention the Labs ( Liapides), a socio-cultural and dialectal Albanian subdivision, some of whom had converted to Islam during the Ottoman Empire era.