Well then try ctrl-shift B (keymapping: "toggle bookmark ...")
Good suggestion, thank you Martin.
If find it's not quite as easy to visualize as M.E's popup but, it is definitely a substantial improvement over having to navigate to the menu to see what bookmarks are set.
Well its a question of how it can be visualized in a popup menu.
Maybe Icons could be greyed (not sure if for those already set, or those not yet set).
That would need to be done before the menu is called, since all the menu entries must be kept enabled.
Maybe the text could contain a hint.
Maybe a checkbox or radio or ... can be added as indicator.