It's irrelevant for eBooks what your Libre Office uses. Similar nearly identical fonts from different sources have different names because the names are usually copyright. There may be very minor differences in two fonts also, resulting in different names. ITC owns a lot of names. Comic Sans, Arial, Courier New, Times New Roman and all the Lucidia fonts I think are copyright Microsoft names. In the intermediate CSS for an eBook (in the HTML or a related file) the fonts to use are named with a list of aliases. Most systems have a default for monospace (Courier, Lucida Console etc), sans (Arial, Verdana, various sans serif) and serif (Times, Times Roman, Times New Roman, Book Antigua, Georgia etc).
So the only things you can assume a target Web Browser, other PC user, eReader:
- A proportional font with serifs like Roman
- A proportional font without serifs, ie. sans serif
- A monospace, non-proportional font, usually serif or else an "i" is daft compared to an m H w X Z etc.
Usually all of these can be about 5 obvious sizes
- H1 (Largest Header)
- H2
- H3
- Normal/body
- small (for small footnotes , superscript or subscript)
H4 to H6 are usually too similar to other sizes so eBook auto TOC generation is usually set to use H1, H2 and H3
Styles are usually
- Normal
- Bold
- Italic
- Bold Italic
Often superscript or subscript automatically selects small. The existing Font & style is usually used but some systems may only use Courier Normal.
Sometimes
strikeout is available.
Note that if you open ANY document on an different PC (that isn't a PDF with embedded fonts)
the layout will change unless the destination user has the same paper sizes available and all the fonts you used already installed. That's why there are two kinds of Postscript and PDF (embedded and use local equivalent). So that documents are really identical on different computers and printers.
I used to give courses in 1990s in Wordprocessing and Desktop publishing. I had systems set up to demonstrate the pitfalls of relying on a font when electronically giving a document to someone else.