(from V5 land)

I'm using a forum that uses UBB.Classic.
(v6.7.2)

I can tell that it knows how to make a URL to an individual post..
(bec., eg: search returns such links)

..but I don't know how to make one.

Still does not make any sense.
Please provide the url to the site.
So we can see what options are used for URL's

In the boards that I'm participating in, anyway, there's a tiny little page icon at the extreme left of an ~info bar~ at the top of each post.

Its tool tip is (only) "-".

But it has associated with it the URL to that post.
(which shows up in the status bar when you hover over the icon)
(You can't get it via right-click / Properties..
..but you can via right-click Copy Shortcut.)

(OTOH, *some* of these forums (confusingly) re-write the URL when it's used (s.t. something else is what appears in the address bar.)


(Just thought that info like this ought to be available to people.)

Okay.
You do realize that classic boards reached their end of life years ago?
Also as a user not a admin you have limited usage to features that may be or not available.

Also as a user you have no control on how the URL's are posted.

Also depending on the version of the obvious very old version, some have the ability to show spider friendly Url's

Last Is, since this is a very old version. It is very hard to determine what you are looking at without a link to the actual page.
If you are unwilling to post a link to the page then not to many people can help you. Since this is a non supported version.

Charles wrote the spider-friendly url's into .classic years ago. Are you asking how ubb handles writing the url? If so, I believe the file is in /cgi/ubb_new_topic.cgi, or ubb_lib_posting.cgi or something similar. You can open the file in a text editor and read - he was pretty good at least a short description of what each function did.

If you're just wanting to grab the url, click into the topic and the url will be in the address bar.

I'm not sure how technical you were wanting the answer to be

Check

sub FETCH {

toward the bottom of ubb_lib.cgi it has some routines for spider-friendly urls.