Scenario
As an admin or content owner, you want to know about the system settings and notifications that can automatically change settings and notifications for existing content, and you want to know how the cascading works.
Cascaded settings
Settings that can cascade from system settings to existing content, or via other content dependencies, are called cascaded settings. Here are four big ideas to understand:
There are some attributes that are set upon creation of a content item and are not impacted by cascaded settings. These can only be updated by editing individual content items.
Other settings (called cascaded settings) for a content item automatically change if they are using the system default and an admin changes the setting on which the default is based. Notifications set at the System Settings level cascade to content in the same way.
Cascaded settings and notifications apply to content dependencies as well. If you change a cascaded setting or notification on an event type (soon to be called event series), it can automatically update already-scheduled events based on that type.
As an admin, if you change a cascaded setting or notification on the system level, it updates all content using the default for those settings, including event types and the events based on those event types.
Settings that can cascade to existing content
Updates to Attendance Policies, Notifications, and some other settings on the system level can cascade to already-existing content. In Settings, this applies to Events, Mentorship & Office Hours, Content, and, in time, to some other categories.
Any other attributes or settings outside of these for existing content can only be updated on the content items themselves.
Live events have another layer of cascaded settings as changes made to event type settings can cascade to already-scheduled events of that type. This creates cascaded settings on three levels: System Settings > Event Type > Events.
How changes to settings cascade to existing content
As long as content items are using system settings as defaults, editing a cascading setting updates already-existing content.
When you access Edit pages for existing content, a gear-checkmark icon indicates settings that use the system setting as a default, and thus will be updated if you edit the corresponding setting at the system level. The undo button indicates settings that are not using the system settings, and thus will not be updated if you edit the corresponding setting at the system level. If there is no gear-checkmark icon or undo button for a content item setting, cascaded settings have no impact on it. It can only be updated at the content level.
For live events, gear-checkmark icons and undo buttons on the Edit event page indicate whether settings are using the event type defaults.
Go deeper
Not using system settings or event type defaults
Any time you edit a cascaded setting for a content item, the gear-checkmark icon switches to a red undo button, indicating that the setting is no longer using the default (from system settings and/or from an event type). This happens even if you clear a value and then enter the same value that was already there. While this will not change the setting itself, it will prevent changes to that setting on the parent level from updating the setting for the content item.
You can click the undo button on a setting to return it to the system setting (or the event type) default. If that default has changed since you updated the setting on the content item, the setting will default to the new value, not the value present when you first made the change.