Published in 1970 the information on the first edition dust jacket, illustrated by Norman Weaver, reflects two contemporary changes.
Firstly, though unseen on this scan, it was issued with an ISBN (International Standard Book Number) comprising of 10 digits, in this case 0 00 221723 6.
The ISBN, introduced in 1970, was based on the 9 digit SBN (Standard Book Number) code, which had been introduced in 1965 and the 10 digit code was itself superseded in 2007 by the present 13 digit ISBN code.
Secondly, that of decimalisation. As the publishing date was close to the UK decimalisation date of 15th February 1971 the dust jacket shows the price both as 25 shillings and £1.25 net.
Image: © HarperCollins Publishers Ltd.