I often have several tabs open. I need the tab on the far right all the time, which is why it should stay that way.
But of course I always manage to “overwrite” it by mistake. I can open and close tabs in the context menu, but unfortunately I can’t “block” them. Is there any other way to do this?
If not, I would suggest introducing such a possibility. I am probably the only person on the planet who would like this. 
Thanks.
No, there is no function to lock a tab in a certain position or with certain content.
OK thanks. And am I the only one who would like this or could you imagine adding such a function at some point?
I can imagine a great many things 
However, this is the first request I can recall and development would have to assess the feasibility and broader appeal of adding it.
That’s good 
The idea is not mine, by the way. I can only confirm that it is useful.
From the manual of another app:
12.2.1 Locking the Editor
A tool that can save you a lot of time (…) is knowing how to essentially turn off navigation. The editor (…) can be locked with the Navigate ▸ Editor ▸ Lock in Place menu command (⌥⌘ L) . The header bar for the editor will be changed to a dark grey (or lighter grey, in Dark Mode) and will have a lock icon added to the right hand side.
