A notable change has just gone live: the Teaser on CMS pages is has been renamed to Subtitle, and gained some new functionality, both to make it more understandable and more useful!
Previously Teaser was quite a confusing thing for a page - as it didn't show up on the page itself and was only visible if you used an Includelet like Filtered Item List to show a listing of pages.
It has now changed in the following ways:
Hopefully this is a useful and understandable improvement to your editing experience! If you have any questions then please reply to this forum post and I will add clarification.
Joe - Voice Admin