I always liked the way of describing grades as

grade 1 take the mother in law
grade 2 take the girlfriend
grade 3 take the wife
grade 4 take the mistress
grade 5 take the photographs
grade 6 take the mother-in-law

Change to suit your sex

old joke I know but someone might not have heard it
--
Dave Manby
Details of the Coruh river and my book "Many Rivers To Run" at
http://www.dmanby.demon.co.uk