What does SZ stand for?

I was just looking at the event's going on in my local area and I don't really know where most of the venue start points are and so was looking at the bit marked venue on the site below

http://www.iwight.com/news_events/event_search3_c.asp?Ev_ref=5124

and it has "SZ 325 855" in brackets, so what does SZ stand for?

I presume that the is a blatantly obvious question and I'm missing something:flag:

 

Hi Aesculus, hope this is of some help.:thmb: 02

http://keithbriggs.info/AS_networks.html

 

I think they are map references. SW is one of the 100km square blocks that the UK is broken into. 325 is the x co-ordinate (ie across) within that area and 855 is the y co-ordinate (ie up). http://www.ordnancesurvey.co.uk/oswebsite/gi/nationalgrid/nationalgrid.pdf (you need Adobe to access this reference)

 

You will find the map reference I gave you covers what has been said. Hope it it has been of some help.

 

Thanks everyone!