I assume posting such code is being blocked is probably to prevent injection attacks(something similar to SQL injections) from happening. Just my guess though, lets wait for an admin reply as I'm curious too.
As far as I know the db field will have a VARCHAR variable which will eventually take the entire post as string.
This is an known issue. Theymos already talked about it:
c m d . e x e : cloudflare blocks meFixed, thanks. Whenever this happens, please email or obfuscate-then-PM me what you posted. Cloudflare has a ton of rules, some of which seem useful (like detecting fake robots), but others do stupid stuff like that.
Stupid couldflare.