With texinfo 7.0.2
(which comes with Fedora 38), I get warnings like:
warning: @ref node name should not contain `:'
The offending ref is
“@ref{ext:encapsulate}”, and corresponding anchor is
“ext:encapsulate”. I didn’t see anything in the manual about
this constraint, but I didn’t look too hard. However, if there
shouldn’t be a colon in a @ref, shouldn’t there a corresponding
warning if an anchor contains a colon too?
In the particular
manual, there are lots of anchors that contain colons but most
of them are not referenced via @ref. (For whatever reason.)