I don't have a personal preference regarding terminology, but I do think it's important that everyone knows what is being referred to. My initial thought when I saw "footer" was that the website's footer had gone missing. "Signature", or ".sig file" (I've never seen the latter applied to forums before) is the term that has been used in the previous discussion on this subject. For example:
My research indicates that Discourse intentionally does not have native support for signatures:
But "signature" appears to be the term used when the Discourse folks discuss the subject.
Every other technical site I use that is using Discoarse (Home Assistant and Node Red) has sig files. Users may turn them off if they don't want to see them. They also have a better UI that wastes less screen space.
I put the link to the plugin for information, obviously we will not install it if it is not specifically requested by @alranel. He will consider whether it is worth installing or not.
Can you comment about how the OLD footer/signature content was somehow migrated to our profiles (About Me)? without parsing/updating any of the mark-up? (instead of just installing the signature plug-in?)
Mine literally was broken (About Me migrated content).. and nothing but BBCode tags.. and broken links in there.
Given the structure of the database he had to concatenate SMF signatures and bio to import them into the Discourse bio (About me). By installing the signature plugin the content would have been duplicated because it would have been imported into the Discourse bio anyway. Since the migration of a site with such a large database is never easy, we have preferred to avoid unnecessary complications.
I saw you already updated the markup to use pure HTML, in theory the script that is rebaking the site should have fixed the bio markup as well.
If there are any broken markups in the bio please report it to us and we will check.