They are suggesting it would be a good idea to introduce measures to calm house price rises if they go beyond a suggested annual average price rise trigger, by using their regulatory powers to restrict the type of mortgages some of the lending companies might be able to offer.
This seems like a very interesting suggestion to me - indirect measures or financial instruments that we could adopt to prevent bubbles like this occurring seem eminently sensible to me, and very much in the interest of the banks, consumers and hence governments.
http://www.telegraph.co.uk/finance/personalfinance/houseprices/10305771/House-price-inflation-should-be-capped-at-5pc-RICS-says.html
They are categorically NOT suggesting that statutory or mandatory controls or measures be introduced that would prevent homeowners from setting whatever asking price they want to their property, which is how several contributors to this thread appear to have interpreted it.