Building upon the Placeholder Overrides functionality described in the last post, this post describes a small customization that enables any page template to bind multiple placeholder settings items to the same placeholder key. This is very useful in multi-site implementations.
A multi-site Sitecore implementation is when multiple different websites are deployed into the same Sitecore instance. Each site has its own unique set of renderings and templates. However, even sites that look and function completely different may still share a common set of generic renderings, like grid structures or an image carousel.