http://groups.google.com/group/symfony-devs/browse_thread/thread/debdacb2f6f9098c/05d21e961c351eb6#05d21e961c351eb6

I advice symfony developers to update the documentation and stress the usage of quotes in YAML files, because this is often the source of problems, if (for example) brackets are used in the text (string data types).

data_1: some text here works well
data_2: and (for example) this one fails due to usage of brackets
data_3: this will strip # this part, because it is commented out
data_4: "this still works again # ()()() # because it is enquoted in
double quotes"

I ended up with all strings enquoted in double quotes in my YAML files and for now on I strictly follow this rule.

Andrejs Verza