https://orgmode.org/manual/Internal-Links.html -- "A link that does not look like a URL—i.e., does not start with a known scheme or a file name—refers to the current document. You can follow it with C-c C-o when point is on the link, or with a mouse click (see Handling Links)."
That's exactly what I was trying to do -- just link to a different part of the same document.
Following the Internal Links page's recommendation, in the target outlined, I created:
:PROPERTIES: :CUSTOM_ID: xyz :END:
(Not really "xyz" but I don't want to include a person's name here.)
Then the link at the source:
Now, when I click on the link, or C-c C-o, I get a dialog to "visit tags table"... ???
I guess custom_id is implemented in a later org version?
How to do this? I just want to link to another node in the same document without adding junk into a system-global org-id table.