Spanish
old Spanish customs (or Spanish practices) long-standing though unauthorized or irregular work practices.
☞ This expression has been in use in printing circles since the 1960s; it is often used humorously to refer to practices in the British newspaper printing houses in Fleet Street, London, formerly notorious for their inefficiency. The reason for describing such practices as 'Spanish' is not known.
2009Guardian With a postal strike ballot underway I see Royal Mail management again accusing the workforce of protecting 'old Spanish customs'.