org-block-regexp

org-block-regexp is a variable defined in `org.el'.
Its value is

"^[ 	]*#\\+begin_?\\([^ \n]+\\)\\(\\([^\n]+\\)\\)?\n\\([^]+?\\)#\\+end_?\\1[ 	]*$"

• This variable may be risky if used as a file-local variable.

Documentation:
Regular expression for hiding blocks.