# Brackets in .Rmd code blocks

I am making some R markdown documents for my stats class. I've noticed I get an error in some functions when I have a code block with {r} instead of just r. Like so...

 r
this code will be fine


 {r}
this code will have an error



When should I be using the brackets for codeblocks in .Rmd and when should I leave them out?

Does it work without a space between the  and the {r}? It may be that the Rmd processor is getting confused about the spaces, but ignoring the bare r`, and assuming the code is R by default.