FileNameJoin[{
  $InstallationDirectory,
  "SystemFiles",
  "FrontEnd",
  "TextResources",
  "Macintosh"
  }]

...

Item[KeyEvent[">", Modifiers -> {Control}],
FrontEndExecute[{
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"->",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After]
}]
],

Item[KeyEvent["[", Modifiers -> {Shift,Control}],
FrontEndExecute[{
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"<|",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After]
}]
],

Item[KeyEvent["]", Modifiers -> {Shift,Control}],
FrontEndExecute[{
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"|>",After],
FrontEnd`NotebookWrite[FrontEnd`InputNotebook[],"[AliasDelimiter]",After]
}]
],

...