Just a quick note that you should all be aware that the 2014 Blue Book regulations regarding Yellow Flags have been revised (after th ebook was printed) for 2014. The changes were highlighted in the MSA magazine in December 2014, also see the link below (page 4 I believe)
http://issuu.com/msauk/docs/msa_news_no44_dec13_web?e=6613824/6055558
Basically, the change is to legitimise the use of Double Waved Yellows in club racing in the UK. How it will work will have to be seen...
Cheers