AllowReverseGroupClose is an option for Cell that specifies whether a cell group can be reverse closed.
ButtonFunction is an option for the low-level function ButtonBox that specifies the function to execute when the button is active and is clicked.
Overscript[x, y] is an object that formats as OverscriptBox[x, y].
Underoverscript[x, y, z] is an object that formats as x_y^z.
Underscript[x, y] is an object that formats as UnderscriptBox[x, y].
PageFooters is an option for notebooks that specifies what should be inserted as the footer of each page of a notebook when it is printed.
PageHeaders is an option for notebooks that specifies what should be inserted as the header of each page of a notebook when it is printed.
WindowTitle is an option that specifies the title to give for a window.
"AboutBoxDialog" is a front end token that opens a notebook containing information about Mathematica.
Close
(Mathematica Front End Token) "Close" is a front end token that closes the input notebook.