"We have a few important announcements concerning the remaining rounds of the BIWS supported by Mirage.
Due to unforeseen circumstances we have had to make a change to the control tyre that is used for our race event. The Nosram VTEC 27R tyre part number NR95052 is currently unavailable to the model shops and this situation may or may not be rectified by the end of the series.
Therefore we will also allow the Nosram VTEC 30R tyre part number NR95053 to be used. These tyres are a slightly harder compound than the 27R compound but as proved at the juniors are a very good tyre for grip and last even longer!
The control tyres allowed at the remaining rounds will be;
VTEC 27R NR95052 RRP ú12.49 a pair
VTEC 30R NR95053 RRP ú12.49 a pair
Finals Race Date
Unfortunately Don Valley will not be available for us on the 16th March as planned. This is due to a very big corporate event which is taking place in numerous halls around Sheffield that weekend.
The BIWS Finals will be held on MARCH 23rd 2008.
Please adjust your calendar and if you can not attend the new date please let the race organisers know by emailing email@example.com
Thank you for supporting the premier Northern Indoor Championships, the BIWS."
Source - http://www.rc-area.co.uk/blog/?p=1888