▁Limited ; ▁and ▁the ▁Bank ▁of ▁China ▁( H ong ▁Kong ) ▁Limited . ▁Notes ▁( H K $ 1 0 ▁only ) ▁are ▁also ▁issued ▁by ▁the ▁H K MA ▁itself ▁because ▁of ▁the ▁continu ing ▁demand ▁for ▁small ▁value ▁notes ▁among ▁the ▁public . ▁ ▁History ▁ ▁As ▁a ▁response ▁to ▁the ▁Black ▁Saturday ▁crisis ▁in ▁ 1 9 8 3 , ▁the ▁linked ▁exchange ▁rate ▁system ▁was ▁adopted ▁in ▁Hong ▁Kong ▁on ▁October ▁ 1 7 , ▁ 1 9 8 3 , ▁under ▁the ▁recommendation ▁of ▁Y . C . ▁J ao , ▁through ▁the ▁currency ▁board ▁system . ▁ ▁The ▁re dem ption ▁of ▁certific ates ▁of ▁inde bt ed ness ▁( for ▁backing ▁the ▁bank notes ) ▁were ▁sent ▁out ▁by ▁note - iss uing ▁banks ▁to ▁p eg ▁the ▁domestic ▁currency ▁against ▁the ▁US ▁doll ar ▁at ▁an ▁internal ▁fixed ▁rate ▁of ▁H K $ 7 . 8 0 ▁= ▁US $ 1 . ▁ ▁The ▁Hong ▁Kong ▁Mon et ary ▁Author ity ▁( H K MA ), ▁Hong ▁Kong ' s ▁de ▁fact o ▁central ▁bank , ▁author ised ▁note - iss uing ▁banks ▁to ▁issue ▁bank notes . ▁These ▁banks ▁are ▁required ▁to ▁have ▁the ▁same ▁amount ▁of ▁US ▁dollars ▁to ▁issue ▁bank notes . ▁The ▁H K MA ▁guarante es ▁to ▁exchange ▁US ▁dollars ▁into ▁Hong ▁Kong ▁dollars , ▁or ▁vice ▁vers a , ▁at ▁the ▁rate ▁of ▁ 7 . 8 0 . ▁When ▁the ▁market ▁rate ▁is ▁below ▁ 7 .