When building your website, you may need to add new content placeholders to a layout to give you more flexibility with adding new content to your site.
A content stack can be added to your layout by using the following syntax:
Once this has been added to the layout, a new placeholder will appear on a CMS page that uses the layout.
There's no need to create multiple placeholders for different kinds of content to be added in the same layout - the placeholder has the capability to add new content items as needed. A single content item or multiple content items within a placeholder is called 'content stack'.
In the above example, a single placeholder called (CMS_OBJECT_CONTENT) is in the middle column, but when looking at a classic ‘Contact Us’ page that uses this layout, you will find 2 content items in that stack, as shown below.