While sharing your word documents, you may want to restrict them from editing to limit how much others can edit and format the document. For example, you can force all to track changes or prevent formatting changes. This is different from "mark as final" which is a feature allows you to focus on reading. Please see below for details:
Step 1: Click the "Review" tab from the ribbon;
Step 2: Click "Restrict Editing" and the "Restrict Editing" pane will appear on the right;
Step 3: Check the box "Limit formatting to a selection of styles" and click "Settings" below;
Step 4: In the new window, deselect the styles you do not change and click "OK" once you complete;
Step 5: In the "Editing restriction" area, check the box of "Allow only this type of editing in the document", and click the small triangle to select one of the four options: Tracked changes, Comments, Filling in forms, and No changes (Read only);
Step 6: Click "Everyone" or choose users who are allowed to edit the selected part;
Step 7: Click "Yes, Start Enforcing Protection";
Step 8: In the new dialog box, type your password to restrict from editing;
Step 9: Click "OK" at the bottom and save the document by using shortcut "Ctrl+S" or clicking the save button.
Step 10: If you want to stop the protection, please click "Stop Protection" at the bottom from the "Restrict Editing" pane.
Step 11: Type the password, and click "OK" at the bottom in the new window.