What is unprotected sheet in Writer?

In the list of keyboard shortcuts (Under Tools-Customize-Keyboard) the description for the shortcut key Ctrl+Shift+T is “unprotected sheet.”

Are there sheets in Writer? What does this shortcut do?

Does that shortcut have a radio button for Calc only in the top right of the dialog box?

No, the radio button is for Writer. I am wondering if it is a mistake.

I poked around and found that this shortcut removes cell protection for the entire current table (or all selected tables). I imagine that the name refers to “sheets” because it is used primarily for sheets in Calc.