307 phone button on radio stalk

[fruitnveg]

Hello all,

I have a 2001 307 with the Clarion PU-2471 (I think that's the right model) RD3 CD player, so nothing special, but my radio control stalk has a phone handset graphic on it, suggesting the source change button can also answer a phone - is there anythign on the market that works with that button? Or is it just that they used the same stalk for all the radios right up to the Satnav/Phone combo?

Many thanks.