I would like blocks like begin_html/end_html to be fontified just like begin_src blocks are.
I would also like to define my own source blocks for clojure (basically a shorthand) and also have them highlighted. Heres what i have to turn on fontifying and define a block.

(setq org-src-fontify-natively t)
;; define #+clj as start of clojure code block and #+end as end of block
(add-to-list 'org-edit-src-region-extra 
   '("^[ \t]*#\\+clj.*\n" "\n[ \t]*#\\+end" "clojure"))

Ive also noticed that the code block (#+clj ... #+end) doesnt fold - however, if i define the block as begin_clj and end_clj it will fold, so im guessing org assumes a certain block format for folding code.

Any way to do the above two things?