When visiting a permanent link to an old revision of a page, a notice is displayed at the top alerting the reader (encoded at en-WP here, I think; see an example in practice here). This notice is not just informative for readers/editors, but an important tool against abuse, since otherwise someone could vandalize an article and then link to the old revision to continue propagating the vandalism even after it's reverted.
However, it is possible to link to a section of an old revision (example), and this presents an avenue for abuse, as someone could do so, and the recipient would not see the notice unless they scrolled up.
Therefore, I propose that the notice be redesigned so that it remains on the page as the reader scrolls. As part of this redesign, it could also be visually improved, for instance by adding a caution icon and a title.
(Note: I'm following-up from proposal on en-wiki here)