about V functions in lisp documentation

In Visual Lisp documentation it is mentioned that if we have to call some activex method using VLISP, get its signature form the VBA reference and add VLA to its start.

for example vla-addline, but their are some 'V Functinos' in the VLISP documentation, are these methods written specifically for VLISP and not accessible from

other programming langauges such VBA and if its not the case then why these V functions are not mentioned in the VBA documentation for example vl-String->list.

thanks.