"Thank You" Kappy, for the prompt response.
I am in the process of installing / converting my home computers over to Catalina, and wanted to be sure that favorites (programs, extensions, add-ons, fonts, etc) made it through the process. I began with three and will proceed through the rest. In reaching out I wanted some assurance that .otf fonts would be compatible with Catalina, & you have given me hope that they do, meaning that I will contact the original source again IF .otf's are NOT supported.
I was looking for "my font" that I had installed beyond the system fonts, which was titled "Andale Mono MT Pro", and which I had downloaded (12/12/2011 6:48:21 PM PST) from Font.com, https://www.fonts.com/, and which also included a BOLD font. As nice as the Andale Mono font is, it lacks the bold feature which I sometimes use.
You have given me some pause for thought now, and it may be that I did NOT install this font (.otf) on the computers in question, because the time frame was so long ago, 12/2011, and I have 11 computers in the family which I manage & try to keep straight on what is on each.
Up to now I have been able to get through macOS problems with terminal (bash (scripts), & am now attempting to learn ZSH (because of the new default)), and the use of downloadables, as needed — so this is my first day on forums, and I am delighted with the prospects of solving more extended problems through the experience & advice of others. Again, I "Thank You".
So, my last question is: how do I close (or call for closure) of a post?