Phocaean red slip (PRS) is a category of terra sigillata, or "fine" Ancient Roman pottery produced in or near the ancient city of Phokaia. It is recognizable by its thin reddish slip over a fine fabric, often with occasional white (lime) inclusions. The main period of production is the late 4th century AD into the 7th century. All forms are open bowls or dishes. Later forms have stamped decoration. The most widely used typology was defined John Hayes in his book Late Roman Pottery, where the ware is called "Late Roman C". The supplement to that volume established the name "Phocaean Red Slip". Hayes form 3 and Hayes form 10 are the most widely exported forms, appearing in the western Mediterranean and also in the British Isles.