BS denotes an ‘old style’ British Standard prepared in the United Kingdom.
BS EN denotes a European Standard adopted as a British Standard and identical to a national standard in all countries of the European Union as well as Iceland, Norway and Switzerland.
PD is a Published Document that is not a British Standard but a (guidance) document published by the British Standards Institution, which gives guidance on the use of a BS EN or amplifies it.
w/d indicates withdrawn.
A number in brackets is the year when the standard was reconfirmed.