The Yellow–Stripe for All Non-Muslims
“The Code of Omar (Umar) … compelled all non-Muslims to wear a stripe of yellow. It prohibited them riding on horseback, directed them to use wooden stirrups, when riding mules, and forbade them erecting standing tombstones in their cemeteries. Their children could not be taught by Muslim teachers, they could aspire to no office of authority or of trust; nor could they build new houses of worship, or display religious symbols in public.”
Source: De Haas, Jacob; History of Palestine – The Last Two Thousand Years. p 135