So in the “new site” migration that happened… a few years ago… lots of stuff worked, plenty of stuff broke.
I found another example that may be worth reviewing for updating previous stuff.
In this example : Express - What is the 'Name Mask' in data objects? - concrete5
One of the later comments refers to : https://www.concrete5.org/about/blog/community-blog/concrete5-821-now-available
Which now 404’s, and as a result that link is now useless from a historic perspective. Looks like the FQDN change is what probably broke it, not entirely sure. But I suspect there’s plenty of examples of this in “old website” content.