I'd like to delete some, not all, from the drop-down list (top/right side of screen) . Can I do so right there? Or do I have to muck about in different areas of the website?

Thank you.

Old messages will drop off themselves eventually or you can click to see all notifications. Scroll down to the bottom of the page and you will see options to delete all or only specific notifications.

Thanks for the pointers. What will they think of next?