Men's toilets are marked 'Herren' (or just 'H'), the ladies' 'Damen' (or just 'D').
Public toilets in southern Germany's city centres are almost non-existent. Instead use facilities in department stores, railway stations, markets, beer halls and other public places.
Toilets are rarely free and those at large railway stations can charge a silly €1 to spend a penny. At some facilities payment is by donation, thus you pay as much as you like. At others there's a price list.
Sanifair toilets charge €0.70 but you receive a €0.50 voucher to spend in the establishment in which it is located. Annoyingly this type of facility has spread in recent years from motorway service stations to other places such as department stores and railway stations. Many jump the low barriers.
Toilets are normally clean, well maintained and not of the squat variety, though some are of the slightly off-putting 'reverse bowl design', not common in the UK or US.