Set Marks on a Vimium Webpage You Want to Jump Back To

Vimium's "marks" feature lets you mark positions in the current tab and across tabs. These are positional markers that you can jump back to. For instance, as you browse a huge page of documentation or a massive forum discussion, you can leave a series of "dog ears" to sections or conversations that you'll later want to revisit. Each tab supports its own set of lower-case letter marks. Upper-case letter marks are shared across tabs allowing you to seamlessly move between a specific set of tabs regardless of how they are arranged.