the one recently used to access the? now if we have 4 pages : A,B,C and D
-page A has a FORWARD link to page C,
-page B has a FORWARD link to page C,
-page C has a FORWARD link to page D & a BACK link to A & B,
-page D has a BACK link to page C,
(if u draw this with circiles and arrows it'll...