<Tr> <Td> </Td> <Td> This article does not cite any sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2008) (Learn how and when to remove this template message) </Td> </Tr> <P> Hook flash or flash (known in the UK as "recall") is a button on a telephone that simulates quickly hanging up then picking up again (a quick off - hook / on - hook / off - hook cycle). This action can signal the telephone exchange to do something . A common use of a hook flash is to switch to another incoming call with the call waiting service . Another use is to indicate a request for voice conferencing, for example, a user may use a procedure like the following to initiate three - way calling: </P> <Ol> <Li> Pick up phone handset (causing the line to be off - hook). </Li> <Li> Hear a dial tone </Li> <Li> Dial the first number and greet the first party </Li> <Li> Press the hook flash button (or quickly tap the on - hook sensor on the phone) </Li> <Li> Hear a stutter dial tone (a series of beeps followed by another dial tone) </Li> <Li> Dial the second number and greet the second party </Li> <Li> Press the hook flash button again . </Li> </Ol> <Li> Pick up phone handset (causing the line to be off - hook). </Li>

Where is the flash button on my phone