Once there was a real distinction in clothing between blue-collar workers and white-collar workers out of which the figurative sense of manual versus clerical staff evolved. Recently the term pink-collar worker has been invented to describe the female equivalent of the (assumed male) blue-collar worker, which is particularly applied to women who assemble electronic equipment and run back-office data-entry systems (the term may have originated in the title of a book by Louise Kapp Howe in 1977). More recent still are gold-collar workers, highly-skilled individuals who know a great deal about several areas of their company’s work, are frequently crucial to its continuing profitability, and who — it is argued — must be managed by techniques that take their special qualities into account. The term was reportedly invented by Professor Robert E Kelley of Carnegie Mellon University, and forms the title of his 1985 book on managing this new type of employee. He also uses the term gold-collar manager for those who supervise them. Other terms which have been used are knowledge worker (itself at least 15 years old, though it hasn’t yet reached most dictionaries), new economy worker, and professional eclectic.