TYPO3 Core

There is a checkbox Show in Section Menus in the Access-tab of nearly all CEs.
But some CEs still are missing this feature when they are selected
as a content-element using the Type select-field.

The checkbox to enable the CE for the sectionIndex
will disappear from the Backend if you select Shortcut (or Mailform for ex.).

So at the moment you have to use a work-around and switch back to
another content-type like Text,
choose enable/disable for the sectionIndex-checkbox,
reselect your wanted content-type like Shortcut
and you will finally get what you want:
Your Shortcut is taken care for in the sectionIndex-menu.

So my suggestion is:
Please enable the checkbox for Shortcut and other CEs who still
do not show this field in their BE dialog.

The working function to show up/hide the CE in the sectionIndex-menu are already
implemented and ready to use in typo3 v7.6!
And by the way: This is a great new feature!
Use it in responsive layouts and enjoy.