An answer on Unix & Linux Stack Exchange led me to look at the manual page for console devices on Linux operating systems.
It turned out that because of a lack of coördination, an entire family of Linux operating systems lost its manual page for these devices years ago.
The Debian people noticed the omission in 2014 and updated Debian to install the manual page from the Linux Man-Pages Project.
And the people from that project updated their project to delete that manual page because "Debian and derivatives don't install this page" and "Debian no longer carries it".
So I made some:
console.xml,
vt.xml
They are somewhat better than the original, which explicitly claimed to be incomplete and erroneously conflated the console with the kernel virtual terminals. They address the user-space view of these devices, without going into kernel internals (of things like how console drivers are developed and registered) which the kernel doco spends most of its time talking about.
These manual pages are included with the nosh toolset (from version 1.39) as linux-console(4) and linux-vt(4) manual pages, along with a stylesheet that makes DocBook XML directly legible with a WWW browser (as you can see).
You can obtain them as actual manual pages (readable with the man command) by installing the nosh-terminal-management binary package, or by building from the source package.
(The nosh toolset is available for more than just Linux operating systems, hence the names of the manual pages.)
They are also included in the nosh Guide, which is in the nosh-guide package that is separate from the tools and installable standalone if you like.
You can read them directly from the DocBook XML with a GUI WWW browser as aforementioned, or using the nosh toolset's console-docbook-xml-viewer(1) tool on a terminal.
The result of converting the DocBook XML to HTML with xmlto looks like
and