I'm obliged to an anonymous person who has left a comment on my post about the off licence in Glasgow which pointed me in the direction of a site called Ned v Ned. Go and have a look at it. I'm sure the pictures of the Neds explain what they're all about far better than mere words!
If you want words though, have a look at Glasgow Survival (warning - discretion advised!) and find the "people" link at the top left of the page. This takes you to a page describing various Neds. There are some amusing bits on that site, so have a look round too, but there is a lot of bad language so you might think about not doing it at work!