As a former British colony and territory, technical standards in Hong Kong of today has been largely influenced by that of the United Kingdom, with some exceptions due to local and practical considerations. Electrical plugs and adaptors Before the legislation of the Electrical Products Regulation (a few years prior to the handover in 1997), British standard extension cables, plugs and adaptors were seldom found in the market. Electrical appliances were fitted with 2-pin plugs and quasi-UK three pin plugs (which meant they were compatible with BS 1363 or BS 546 sockets, but the plug itself did not comply with the British Standard). After the enforcement of the regulation, many British standard electrical products are common in Hong Kong market. Some adaptors common in the United Kingdom are not available in Hong Kong. Conversely, local manufacturers develop adaptors for the Hong Kong market and they are not often sold in the UK. Some local manufacturers print the Union Flag on the plugs and extension cables, but these products are not manufactured or sold in the United Kingdom. This practice has not ceased even though Hong Kong was transferred to the People's Republic of China in 1997. Electric sockets (wiring system) Based on the adapted version of IEE Wiring Regulations, the colonial Hong Kong Government published Code of Practice for the Electricity (Wiring) Regulation in the 1990s. This book has been revised several times and the latest version was published in 2009. In Government buildings, public housing estates and Government-sponsored educational institutions, British electrical products (brands include Tenby, MK electric, Federal Electric, MEM, Crabtree, Legrand etc.) are often used. However, these British electrical products are not very popular in the private sector. Some people consider that British sockets are not very good-looking so they prefer other brands. Australia-based Clipsal (produced by Gold Peak in China) is the most popular brand in private buildings, and some Government buildings built after the handover of Hong Kong to PRC in 1997. Telephone sockets Before the handover of Hong Kong, all the domestic telephone sockets installed were BS 6312 British telephone sockets but there was no stipulation on commercial telephone sockets. Both Registered Jack (RJ) and BS 6312 systems were (and are) found in commercial telephone installations. After the handover, the Hong Kong Government started gradually replacing the BS 6312 sockets with American RJ ones. Service providers install RJ sockets, instead of BS 6312 ones, for