Case in disambiguation of variable or function definition of a symbol

[whxvd]

The Emacs Lisp manual states:

[W]hen a symbol has both a function definition and a variable definition, and you want to refer to just one of them, you can specify which one by writing one of the words ‘variable’, ‘option’, ‘function’, or ‘command’, immediately before the symbol name. (Case makes no difference in recognizing these indicator words.)

However, helpful-function seems to only do the disambiguation when, e.g., "function" or "variable" is given in lower case.

(defun f ()
  "Function `buffer-file-name' or function `buffer-file-name'.
  Variable `buffer-file-name' or variable `buffer-file-name'."
  nil)

Following the link to Function `buffer-file-name' or Variable `buffer-file-name' in the helpful buffer for f still asks for disambiguation.