Let me give this unworthy detail another go... But never mind this, really, Aris has got better things to do and most people aren't on this level of thinking at all...
Firefox 52 ESR. Classic Theme Restorer Options > General UI > Page 1 > General UI > Movable back-forward buttons > Hide buttons history popup menu on mouse press: checked. With this option checked, when you hold the back and forward buttons, the context popup menu no longer shows up, it will only show up from right-clicking, which is the standard method to open it. Still, the back and forward buttons have their tooltip (which appears after hovering them for a bit). It's a standard descriptive tooltip that says "Go back/forward one page." But it has a second nonstandard line that reads "Right click
or pull down to show history." The CTR option just mentioned disabled the pulling down part. But the tooltip continues to indicate its existence. The fix is simple.
Code: Select all
#back-button-tooltip label[class="tooltip-label"][value="Right-click or pull down to show history"],
#forward-button-tooltip label[class="tooltip-label"][value="Right-click or pull down to show history"]
{display:none}
There we have. It's gone. (The whole second line, perhaps like Firefox once was; the standard part of the tooltip remains).
Now, explaining the standards, it's something appropriate only for BugZilla, but of course here it is anyway. It's because of consistency. If nowhere does holding right click open the context menus, neither should that happen in these particular buttons. Imagine holding a link to open its context menu. If it's not implemented everywhere, it can't be in this particular place only. As for the tooltips having a second line describing what happens on right-click, it's again really not implemented as a standard at all, so it shouldn't show up here just for these two buttons. For example, right clicking other toolbar buttons results in a menu with options like "Remove from Toolbar" and "Customize...". Yet, their tooltip doesn't have a second line saying "Right click to remove from toolbar or customize." Neither do link tooltips advise of the right click options either. It's just not a thing. Hence why it shouldn't happen in these two buttons alone. (And also, hence the logic for using something like Classic Theme Restorer, although in this case doesn't remove the extra line.)