From the article about pleonasm:
Some pleonastic phrases, when used in professional or scholarly writing, may reflect a standardized usage that has evolved over time; or a precise meaning familiar to specialists, but not necessarily to those outside that discipline. Such examples as "null and void", "terms and conditions", "each and all" are legal doublets that are part of legally operative language that is often drafted into legal documents. A classic example of such usage was that by the Lord Chancellor at the time (1864), Lord Westbury, in the English case of ex parte Gorely, when he described a phrase in an Act as "redundant and pleonastic". The fact that this phrase in itself was a pleonasm is something which probably had not escaped the learned judge, and could be suspected to be evidence of a particularly Victorian legal sense of humour.