The South African Reserve Bank (SARB) published guidance on exchanging withdrawn old-series Big Five ZAR 200 banknotes, reiterating that these notes were removed from circulation after relatively high-quality counterfeits entered the market and the matter was investigated. The SARB notes that the public was asked to exchange old-series ZAR 200 notes at commercial banks by end-May 2010, after which exchanges are only available at the SARB Head Office teller operating from the SARB Johannesburg Cash Centre on Tuesdays and Thursdays between 09:00 and 13:00, on a cash-for-cash basis. Commercial banks cannot exchange the withdrawn notes. The guidance also clarifies that upgraded Big Five ZAR 200 notes bearing the signatures of former governors Tito Mboweni and Gill Marcus remain in circulation and lists key security features for the public to verify, including watermark and perfect registration elements, a windowed security thread with holographic features, colour-changing ink, microlettering, unique numbering and tactile identifiers for visually impaired users.