Courier and Monaco do work just fine.
It’s not due to the two words of the font name. American Typewriter does work properly, too.
See this sample file Mono.pdf
How do you mean that it doesn’t show up? It shows up in the file on my computer when I open it in Adobe Acrobat Reader.
How does it show up for you then?
See herethis snapshot - you can fill out the form. But it does not use the predefined Liberation Mono for the text form box. It does use Courier and Monaco, you may see the difference. But instead of Liberation Mono (a monospaced font) you see maybe Liberation Sans (proportional font without serif).
I guessed maybe it was of the two word font name - but another attempt with American Typewriter was ok, too.
Like this, in Chrome:
I don’t have the two lower fonts, so they’re faked - that’s probably the problem here, that you open the PDF on a computer without a font that the file was designed with. In Adobe Acrobat reader, the lowest boxes fill with dots, as with passwords.
good to know - so it does work for you on Chrome. Which OS?
The strange thing, the text on the right side, Liberation Mono, is shown properly. The text in the text form box is not (here)
You do observe a comparable problem: your American Typewriter is shown ok on the right side, but not in your text form box. Your Monacos look different, too. On the right side, all is ok. Within the text form box only Courier and, for you, Liberation Mono do work. The Monaco and Am. Typewriter don’t. Why?
See my answer, Libre replaces the fonts that you don’t have with ones that should fit the metrics described in the font.
Where and how is this replaced?
I guess we do agree that the fonts show properly within the text. Since those fonts should be included within the PDF, there should not be any problem.
However, for entering text within the form field, this replacement does not work.
Could/Should it work? Why does it need a replacement at all, since on my computer all of these fonts should be available. As you see, for some it does, for some it doesn’t.
I begin to wonder whether this is less a LO topic and more one of PDF readers.