jit-lock-register
jit-lock-register is a compiled Lisp function in `jit-lock.el
'.
(jit-lock-register FUN &optional CONTEXTUAL)
Register FUN as a fontification function to be called in this buffer.
FUN will be called with two arguments START and END indicating the region
that needs to be (re)fontified.
If non-nil, CONTEXTUAL means that a contextual fontification would be useful.