The entry details seem to say that there is unlimited substitution, as long as this is done through the system. I suspect that there will be a lot of movement just before the actual race.

It's a shame that there was no indication ,that I could find, for a limit.

Also, I think it is a bit odd for entries to open before the FRA Calendar has even been sent out. It's not like there wasn't enough time to take entries from say 15th January, and advertise the fact.

I am only entered because I spotted this thread.