Savings institutions will be required beginning Oct....

Savings institutions will be required beginning Oct. 1 to offer prospective borrowers a clear and concise description of their adjustable-rate mortgage programs, according to the Federal Home Loan Bank Board. FHLBB said S&Ls; must provide the information either when a mortgage application form is offered or before the borrower pays any non-refundable fees, whichever occurs first. S&Ls; must also notify borrowers at least 25 days in advance of any change in monthly payments. The new rules were adopted last week and become effective today.