Control-Y

Control-Y is a common computer command. It is generated by holding and pressing the key on most Computer Keyboards.
In most Windows applications this keyboard shortcut functions as Redo, reversing a previous Undo. In some programs such as Microsoft Office it repeats the previous action if it was something other than Undo.
Apple Macintosh systems use for Redo. In general a shortcut on Macintosh using matches up with a shortcut on Windows using , this is one of the most noticeable conflicts.
Many programs (on all systems including Linux) support both and for Redo, due to this conflict. But quite a few remain where only one or the other shortcut works.
Older applications.
 deleted the current line in the "WordStar" word processor for CP/M and MS-DOS. In the 1980s, many text editors and word processors mimicked the "WordStar" command set, making a common synonym for "delete line."
In Borland IDEs it also deletes the current line.
In emacs it does a paste action (known as "yank"). Emacs uses for Undo and Redo.
In vi and vim it scrolls the display up one line.
In the pico and nano text editors this shortcut scrolls one page up.
In SAP GUI it enters block-select mode.