Sometimes partners want/need to curate or customize the event description for a specific group, venue, or variation on the event content to cater to different audiences or venue partners.
When adding a new date that you'd like to customize on the "Details" there is an option to select Yes/No for "Create schedule specific event description" about halfway down the page.
To customize, select "Yes" and the software will pre-fill the existing event description. Then you can customize for the offering without changing the existing original event description for your other dates.
If you decide to return to the original event description, simply select "No" and your new date will expose the same as the original listing.