help-xref-button

help-xref-button is an autoloaded compiled Lisp function in `help-mode.el'.

(help-xref-button MATCH-NUMBER TYPE &rest ARGS)

Make a hyperlink for cross-reference text previously matched.
MATCH-NUMBER is the subexpression of interest in the last matched
regexp. TYPE is the type of button to use. Any remaining arguments are
passed to the button's help-function when it is invoked.
See `help-make-xrefs'.