Can you describe this better? What APIs use that constant; that could be helpful

Otherwise, that app I linked you to has a search function. When I searched for constants that contained the letters JOY, it gave me these results:
Code:
Private Const DIPROP_JOYSTICKID As Long = MAKEDIPROP(15)
Private Const JOY_BUTTON1 As Long = &H1
Private Const JOY_BUTTON10 As Long = &H200&
Private Const JOY_BUTTON11 As Long = &H400&
Private Const JOY_BUTTON12 As Long = &H800&
Private Const JOY_BUTTON13 As Long = &H1000&
Private Const JOY_BUTTON14 As Long = &H2000&
Private Const JOY_BUTTON15 As Long = &H4000&
Private Const JOY_BUTTON16 As Long = &H8000&
Private Const JOY_BUTTON17 As Long = &H10000
Private Const JOY_BUTTON18 As Long = &H20000
Private Const JOY_BUTTON19 As Long = &H40000
Private Const JOY_BUTTON1CHG As Long = &H100
Private Const JOY_BUTTON2 As Long = &H2
Private Const JOY_BUTTON20 As Long = &H80000
Private Const JOY_BUTTON21 As Long = &H100000
Private Const JOY_BUTTON22 As Long = &H200000
Private Const JOY_BUTTON23 As Long = &H400000
Private Const JOY_BUTTON24 As Long = &H800000
Private Const JOY_BUTTON25 As Long = &H1000000
Private Const JOY_BUTTON26 As Long = &H2000000
Private Const JOY_BUTTON27 As Long = &H4000000
Private Const JOY_BUTTON28 As Long = &H8000000
Private Const JOY_BUTTON29 As Long = &H10000000
Private Const JOY_BUTTON2CHG As Long = &H200
Private Const JOY_BUTTON3 As Long = &H4
Private Const JOY_BUTTON30 As Long = &H20000000
Private Const JOY_BUTTON31 As Long = &H40000000
Private Const JOY_BUTTON32 As Long = &H80000000
Private Const JOY_BUTTON3CHG As Long = &H400
Private Const JOY_BUTTON4 As Long = &H8
Private Const JOY_BUTTON4CHG As Long = &H800
Private Const JOY_BUTTON5 As Long = &H10&
Private Const JOY_BUTTON6 As Long = &H20&
Private Const JOY_BUTTON7 As Long = &H40&
Private Const JOY_BUTTON8 As Long = &H80&
Private Const JOY_BUTTON9 As Long = &H100&
Private Const JOY_CAL_READ3 As Long = &H40000
Private Const JOY_CAL_READ4 As Long = &H80000
Private Const JOY_CAL_READ5 As Long = &H400000
Private Const JOY_CAL_READ6 As Long = &H800000
Private Const JOY_CAL_READALWAYS As Long = &H10000
Private Const JOY_CAL_READRONLY As Long = &H2000000
Private Const JOY_CAL_READUONLY As Long = &H4000000
Private Const JOY_CAL_READVONLY As Long = &H8000000
Private Const JOY_CAL_READXONLY As Long = &H100000
Private Const JOY_CAL_READXYONLY As Long = &H20000
Private Const JOY_CAL_READYONLY As Long = &H200000
Private Const JOY_CAL_READZONLY As Long = &H1000000
Private Const JOY_HW_2A_2B_GENERIC As Long = 2
Private Const JOY_HW_2A_4B_GENERIC As Long = 3
Private Const JOY_HW_2B_FLIGHTYOKE As Long = 5
Private Const JOY_HW_2B_FLIGHTYOKETHROTTLE As Long = 6
Private Const JOY_HW_2B_GAMEPAD As Long = 4
Private Const JOY_HW_3A_2B_GENERIC As Long = 7
Private Const JOY_HW_3A_4B_GENERIC As Long = 8
Private Const JOY_HW_4B_FLIGHTYOKE As Long = 10
Private Const JOY_HW_4B_FLIGHTYOKETHROTTLE As Long = 11
Private Const JOY_HW_4B_GAMEPAD As Long = 9
Private Const JOY_HW_CUSTOM As Long = 1
Private Const JOY_HW_LASTENTRY As Long = 13
Private Const JOY_HW_NONE As Long = 0
Private Const JOY_HW_TWO_2A_2B_WITH_Y As Long = 12
Private Const JOY_HWS_AUTOLOAD As Long = &H10000000
Private Const JOY_HWS_GAMEPORTBUSBUSY As Long = &H1
Private Const JOY_HWS_HASPOV As Long = &H2
Private Const JOY_HWS_HASR As Long = &H80000
Private Const JOY_HWS_HASU As Long = &H800000
Private Const JOY_HWS_HASV As Long = &H1000000
Private Const JOY_HWS_HASZ As Long = &H1
Private Const JOY_HWS_ISANALOGPORTDRIVER As Long = &H8000000
Private Const JOY_HWS_ISCARCTRL As Long = &H40
Private Const JOY_HWS_ISGAMEPAD As Long = &H20
Private Const JOY_HWS_ISGAMEPORTBUS As Long = &H80000000
Private Const JOY_HWS_ISGAMEPORTDRIVER As Long = &H4000000
Private Const JOY_HWS_ISHEADTRACKER As Long = &H2000000
Private Const JOY_HWS_ISYOKE As Long = &H10
Private Const JOY_HWS_NODEVNODE As Long = &H20000000
Private Const JOY_HWS_POVISBUTTONCOMBOS As Long = &H4
Private Const JOY_HWS_POVISJ1X As Long = &H10000
Private Const JOY_HWS_POVISJ1Y As Long = &H20000
Private Const JOY_HWS_POVISJ2X As Long = &H40000
Private Const JOY_HWS_POVISPOLL As Long = &H8
Private Const JOY_HWS_RISJ1X As Long = &H100000
Private Const JOY_HWS_RISJ1Y As Long = &H200000
Private Const JOY_HWS_RISJ2Y As Long = &H400000
Private Const JOY_HWS_XISJ1Y As Long = &H80
Private Const JOY_HWS_XISJ2X As Long = &H100
Private Const JOY_HWS_XISJ2Y As Long = &H200
Private Const JOY_HWS_YISJ1X As Long = &H400
Private Const JOY_HWS_YISJ2X As Long = &H800
Private Const JOY_HWS_YISJ2Y As Long = &H1000
Private Const JOY_HWS_ZISJ1X As Long = &H2000
Private Const JOY_HWS_ZISJ1Y As Long = &H4000
Private Const JOY_HWS_ZISJ2X As Long = &H8000
Private Const JOY_ISCAL_POV As Long = &H20
Private Const JOY_ISCAL_R As Long = &H4
Private Const JOY_ISCAL_U As Long = &H8
Private Const JOY_ISCAL_V As Long = &H10
Private Const JOY_ISCAL_XY As Long = &H1
Private Const JOY_ISCAL_Z As Long = &H2
Private Const JOY_OEMPOLL_PASSDRIVERDATA As Long = 7
Private Const JOY_PASSDRIVERDATA As Long = &H10000000
Private Const JOY_POV_NUMDIRS As Long = 4
Private Const JOY_POVBACKWARD As Long = 18000
Private Const JOY_POVCENTERED As Long = -1
Private Const JOY_POVFORWARD As Long = 0
Private Const JOY_POVLEFT As Long = 27000
Private Const JOY_POVRIGHT As Long = 9000
Private Const JOY_POVVAL_BACKWARD As Long = 1
Private Const JOY_POVVAL_FORWARD As Long = 0
Private Const JOY_POVVAL_LEFT As Long = 2
Private Const JOY_POVVAL_RIGHT As Long = 3
Private Const JOY_RETURNALL As Long = (JOY_RETURNX Or JOY_RETURNY Or JOY_RETURNZ Or JOY_RETURNR Or JOY_RETURNU Or JOY_RETURNV Or JOY_RETURNPOV Or JOY_RETURNBUTTONS)
Private Const JOY_RETURNBUTTONS As Long = &H80&
Private Const JOY_RETURNCENTERED As Long = &H400&
Private Const JOY_RETURNPOV As Long = &H40&
Private Const JOY_RETURNPOVCTS As Long = &H200&
Private Const JOY_RETURNR As Long = &H8&
Private Const JOY_RETURNRAWDATA As Long = &H100&
Private Const JOY_RETURNU As Long = &H10
Private Const JOY_RETURNV As Long = &H20
Private Const JOY_RETURNX As Long = &H1&
Private Const JOY_RETURNY As Long = &H2&
Private Const JOY_RETURNZ As Long = &H4&
Private Const JOY_US_HASRUDDER As Long = &H1
Private Const JOY_US_ISOEM As Long = &H4
Private Const JOY_US_PRESENT As Long = &H2
Private Const JOY_US_RESERVED As Long = &H80000000
Private Const JOY_US_VOLATILE As Long = &H8&
Private Const JOY_USEDEADZONE As Long = &H800&
Private Const JOYCAPS_HASPOV As Long = &H10
Private Const JOYCAPS_HASR As Long = &H2
Private Const JOYCAPS_HASU As Long = &H4
Private Const JOYCAPS_HASV As Long = &H8
Private Const JOYCAPS_HASZ As Long = &H1
Private Const JOYCAPS_POV4DIR As Long = &H20
Private Const JOYCAPS_POVCTS As Long = &H40
Private Const JOYERR_BASE As Long = 160
Private Const JOYERR_NOCANDO As Long = (JOYERR_BASE + 6)
Private Const JOYERR_NOERROR As Long = (0)
Private Const JOYERR_PARMS As Long = (JOYERR_BASE + 5)
Private Const JOYERR_UNPLUGGED As Long = (JOYERR_BASE + 7)
Private Const JOYSTICKID1 As Long = 0
Private Const JOYSTICKID2 As Long = 1
Private Const JOYTYPE_DEFAULTPROPSHEET As Long = &H80000000
Private Const JOYTYPE_NOAUTODETECTGAMEPORT As Long = &H2
Private Const JOYTYPE_NOHIDDIRECT As Long = &H4
Private Const JOYTYPE_ZEROGAMEENUMOEMDATA As Long = &H1
Private Const MAX_JOYSTICKOEMVXDNAME As Long = 260
Private Const MAX_JOYSTRING As Long = 256
Private Const MM_AMD_INTERWAVE_JOYSTICK As Long = 6
Private Const MM_CRYSTAL_SOUND_FUSION_JOYSTICK As Long = 26
Private Const MM_DIMD_VIRTJOY As Long = 4
Private Const MM_JOY1BUTTONDOWN As Long = &H3B5
Private Const MM_JOY1BUTTONUP As Long = &H3B7
Private Const MM_JOY1MOVE As Long = &H3A0
Private Const MM_JOY1ZMOVE As Long = &H3A2
Private Const MM_JOY2BUTTONDOWN As Long = &H3B6
Private Const MM_JOY2BUTTONUP As Long = &H3B8
Private Const MM_JOY2MOVE As Long = &H3A1
Private Const MM_JOY2ZMOVE As Long = &H3A3
Private Const MM_NEC_JOYSTICK As Long = 12
Private Const MM_OLIVETTI_JOYSTICK As Long = 8
Private Const MM_PC_JOYSTICK As Long = 12
Private Const MM_WORKBIT_JOYSTICK As Long = 8
Private Const MM_YAMAHA_OPL3SA_JOYSTICK As Long = &H18
Private Const REGSTR_KEY_JOYCURR As String = "CurrentJoystickSettings"
Private Const REGSTR_KEY_JOYSETTINGS As String = "JoystickSettings"
Private Const REGSTR_PATH_JOYCONFIG As String = REGSTR_PATH_MEDIARESOURCES ("\Joystick")
Private Const REGSTR_PATH_JOYOEM As String = REGSTR_PATH_PRIVATEPROPERTIES ("\Joystick\OEM")
Private Const REGSTR_VAL_JOYCALLOUT As String = ("JoystickCallout")
Private Const REGSTR_VAL_JOYNCONFIG As String = ("Joystick%dConfiguration")
Private Const REGSTR_VAL_JOYNOEMCALLOUT As String = ("Joystick%dOEMCallout")
Private Const REGSTR_VAL_JOYNOEMNAME As String = ("Joystick%dOEMName")
Private Const REGSTR_VAL_JOYOEMCAL1 As String = ("OEMCal1")
Private Const REGSTR_VAL_JOYOEMCAL10 As String = ("OEMCal10")
Private Const REGSTR_VAL_JOYOEMCAL11 As String = ("OEMCal11")
Private Const REGSTR_VAL_JOYOEMCAL12 As String = ("OEMCal12")
Private Const REGSTR_VAL_JOYOEMCAL2 As String = ("OEMCal2")
Private Const REGSTR_VAL_JOYOEMCAL3 As String = ("OEMCal3")
Private Const REGSTR_VAL_JOYOEMCAL4 As String = ("OEMCal4")
Private Const REGSTR_VAL_JOYOEMCAL5 As String = ("OEMCal5")
Private Const REGSTR_VAL_JOYOEMCAL6 As String = ("OEMCal6")
Private Const REGSTR_VAL_JOYOEMCAL7 As String = ("OEMCal7")
Private Const REGSTR_VAL_JOYOEMCAL8 As String = ("OEMCal8")
Private Const REGSTR_VAL_JOYOEMCAL9 As String = ("OEMCal9")
Private Const REGSTR_VAL_JOYOEMCALCAP As String = ("OEMCalCap")
Private Const REGSTR_VAL_JOYOEMCALLOUT As String = ("OEMCallout")
Private Const REGSTR_VAL_JOYOEMCALWINCAP As String = ("OEMCalWinCap")
Private Const REGSTR_VAL_JOYOEMDATA As String = ("OEMData")
Private Const REGSTR_VAL_JOYOEMNAME As String = ("OEMName")
Private Const REGSTR_VAL_JOYOEMPOVLABEL As String = ("OEMPOVLabel")
Private Const REGSTR_VAL_JOYOEMRLABEL As String = ("OEMRLabel")
Private Const REGSTR_VAL_JOYOEMTESTBUTTONCAP As String = ("OEMTestButtonCap")
Private Const REGSTR_VAL_JOYOEMTESTBUTTONDESC As String = ("OEMTestButtonDesc")
Private Const REGSTR_VAL_JOYOEMTESTMOVECAP As String = ("OEMTestMoveCap")
Private Const REGSTR_VAL_JOYOEMTESTMOVEDESC As String = ("OEMTestMoveDesc")
Private Const REGSTR_VAL_JOYOEMTESTWINCAP As String = ("OEMTestWinCap")
Private Const REGSTR_VAL_JOYOEMULABEL As String = ("OEMULabel")
Private Const REGSTR_VAL_JOYOEMVLABEL As String = ("OEMVLabel")
Private Const REGSTR_VAL_JOYOEMXYLABEL As String = ("OEMXYLabel")
Private Const REGSTR_VAL_JOYOEMZLABEL As String = ("OEMZLabel")
Private Const REGSTR_VAL_JOYUSERVALUES As String = ("JoystickUserValues")