Must the turban conform to the style worn by Muslims?
Chapter on Wiping over the Khuffayn (Leather Socks)
Al-Mughni
Book of Purification
Primary text
The turban must be styled in the manner of Muslim turbans, meaning that some material must be placed under the chin (muhannakah). This style is characteristic of Arab turbans and offers greater coverage, and removing it is difficult, thus permitting wiping over it, whether it has a trailing end (dhu'abah) or not, according to Al-Qadi. If there is nothing under the chin, and it lacks a trailing end, wiping over it is not permissible because it resembles the turbans of the People of the Covenant (Ahl al-Dhimma) and its removal is easy.
Supporting text
The Prophet, peace be upon him, commanded the act of 'Talhi' (having material under the chin) and forbade 'Iqtitaq' (having nothing under the chin). Umar, may Allah be pleased with him, saw a man whose turban had nothing under his chin and forced some material under it, condemning the style as displeasing, thus preventing wiping over it due to the prohibition and the ease of its removal.