org-dblock-start-re

org-dblock-start-re is a variable defined in `org.el'.
Its value is

"^[ 	]*#\\+\\(?:BEGIN\\|begin\\):[ 	]+\\(\\S-+\\)\\([ 	]+\\(.*\\)\\)?"

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

Documentation:
Matches the start line of a dynamic block, with parameters.