fortran-blink-matching-if is a variable defined in `fortran.el'.
Its value is
nil
This variable is safe as a file local variable if its value
satisfies the predicate `booleanp'.
Documentation:
Non-nil causes M-x fortran-indent-line on ENDIF to blink on matching IF.
Also, from an ENDDO statement blink on matching DO [WHILE] statement.
You can customize this variable.