remove subfield 4 from tag 700 when displaying other others

[cummingsm]

The subfield 4 of the 700 tag contains some cryptic abbreviations, e.g., this example from item/9225344:

Coyote, Peter. nrt ; Clarkson, Patricia. nrt ; Danner, Blythe. prf ; Giamatti, Paul. prf ; Hanks, Tom. prf ; Lithgow, John, 1945- prf ; Platt, Oliver. prf ; Ward, Geoffrey C. aus ; Botstein, Sarah, 1972- pro ; Novick, Lynn. pro drt ; Burns, Ken, 1953- pro drt

The desired result will not include 'nrt', 'prf', 'aus', 'pro', 'pro drt'