Lock Template Frame
When you create templates in the Custom category you have the choice to allow your user's add additional layout elements to the frame or not. You can control this by locking the template frame.
1. Navigate to your template. Then use the Yes / No toggle to Lock / Unlock the template frame.
2. When the template frame is set to "NO", when your users are editing a campaign, the "Grid, Text and Image" blocks will be visible. They will be able to extend their campaign layout with these blocks.
3. If set to "Yes", It will hide the content blocks and your user's will not be able to extend the campaign layout.