The BCC website crashed while I was trying to hunt the information down, but I suspect there is nothing on there. There are very few cases like this each year, so it probably doesn't occur to them to include much information about it.
As Guest55 says, drop them an email or call them to ask what the process is. I suspect the answer will be that it is pretty much the same as for "timely" applications, except that your school preferences will not be taken into account for the first round of allocations on 1st March, but only entered into the next available round after testing has taken place.
Based on the GS I assume you are interested in, that won't be a problem.