[EXI] EXI options encoding

Hello,

I'm reading section 5.4. EXI Options as "EXI options has to be encoded using default options, using build-in grammar and without EXI header". Is it correct? 
 
I think will be logical to use schema-informed grammar during options encoding. If schema-informed grammar is used, where can I find that grammar (not XSD schema) in EXI Grammar Notation?
 
Thank you.