FRS is the act of central banks allowing banks to add money on accounts up to the ratio amount.
In other words. Banks can create money "out of the blue" since most money are just numbers and not actual cash.
Lending out money this way is not affecting any other accounts. No money is being taken from somewhere and put into the lendees account. Instead banks are allowed to create the loan which is debt, not to the bank but to the lendee. To the bank this is an asset to the lendee this is debt.
In other words the bank have more money after they give the loan not less.
It doesn't get much clearer hat than that IMO.
A simple statement on a Federal Reserve web site stating that such a bank has to keep deposits and that the loan comes from new money created should be sufficient.
"The amount of reserves that a depository institution must hold against specified deposit liabilities."
http://www.federalreserve.gov/newsevents/reform_glossary.htm
And here's a table showing the exact percentages of DEPOSIT liabilities:
https://www.federalreserve.gov/monetarypolicy/reservereq.htm...
It doesn't get more definitive than that. And if it were a multiplier, how much can a bank lend out if they have less than $15 million in deposits? Infinity?