From the Sitecore 8 training, I remember that it said that when you edit you the shared layout of a page, it is the layout delta that is saved.
Before the 8.2 version, you could only modify the shared layout through the presentation details interface. You could modify the final layout in the Experience Editor.
Sitecore 8.2 introduced the possibility to edit both the final and shared layout in the Experience Editor. Great stuff! But there is a small issue, when editing the shared layout in Experience Editor, it saves the raw layout, not the delta.
What does that mean? If you edit the templates standard value, the changes will be seen in the pages who don’t have a shared layout value, or a delta. Why? Because the raw shared layout data takes overrides the value from the template standard value.
We brought this to the attention of the Sitecore Support, and got this patch that fixes the issue nicely: Sitecore.Support.144214.
Sitecore Training Recap
Assembling Presentation Information
- Shared Layout option uses __Rendering field
- Final Layout option use __Final Rendering Field
- Going from right to left, if a field has a layout delta, it goes to the field to its left to gather more presentation information.