RVR old chap... Whats the RVR requirements for your flight using your IMCr? 1800m..... You may not take off or land if the viz is less than 1800m......
The requirements for an IR holder are that for SPA the RVR has to be 800m or greater. That restriction may be removed if you are fitted with a fully coupled auto pilot in which case for an IR holder it then becomes the plate minima or the AP minima whichever is greater.....