custom-variable-type

custom-variable-type is a compiled Lisp function in `cus-edit.el'.

(custom-variable-type SYMBOL)

Return a widget suitable for editing the value of SYMBOL.
If SYMBOL has a `custom-type' property, use that.
Otherwise, try matching SYMBOL against `custom-guess-name-alist' and
try matching its doc string against `custom-guess-doc-alist'.