SDM = standard dialog manager, presumably https://docs.microsoft.com/en-us/windows/desktop/WinAuto/appendix-b--standard-dialog-manager-support https://docs.mic

SDM = standard dialog manager, presumably https://docs.microsoft.com/en-us/windows/desktop/WinAuto/appendix-b--standard-dialog-manager-support https://docs.microsoft.com/en-us/windows/desktop/WinAuto/app...