2 Questions:

Has anyone developed a program to remove all foreign language fonts from the LibreOffice Writer program? Before you ask, yes, I have already availed myself of the "fonts removal app" included in the Do These Things First list, but far too many useless (to me) fonts remain.

Has anyone developed a program to replace all existing fonts with a customized list of the standard, most used font types?

Thanks, guys.

I got them.

I deleted obviously foreign sounding fonts by packages. Then I went through a few cycles of

1. Opening Libreoffice and noting terms common to foreign fonts - Noto, Lohit & Umpush(?) were some. Drop to runlevel 3.
2. Grepping my installed packages for those terms, and removing the offending packages.
3. Running 'sudo mkfontdir && sudo mkfontscale'
4. Restarting X, and rechecking Libreoffice.

I'm using slackware, where package lists are in plain text when installed. I'm also set for runlevel 3, so I type startx to get X going. You make the necessary adjustments for your distro.

Fonts are often hidden behind strange names. Hangul is chinese fonts; pinyin is a sort of half way house between chinese hieroglyphics/characters/?? and English for folks learning chinese. There's also Korean, & Japanese characters, alike but different. There's at least 4 distinct chinese dialects, and over half a dozen Arabic ones. Then Indian, Greek, Cyrillic… There's a lot to be catered for.

It depends on where the fonts come from.

I use Apache OpenOffice rather than LibreOffice and that comes with a bundle of fonts I didn't need. I removed all except opensymbol, the default for the mathematical formula editor.

Then there are the fonts that come with the distro. To avoid getting things back again if they are revised, you really need to use the package manager and remove the package that provided them. In Mint, that should be OK. When I installed Debian on an old laptop (the only distro that runs on it!) I found I'd been given complete support for Thai and trying to remove it with the package manager caused a hissy fit. You may also find that some-one has marked a particular font package as a dependency of something important, even though it isn't, so you can't remove it. If you are really fussy (like me) you manually delete the font files and resign yourself to them coming back when you upgrade to the next version of the distro.

In other words, if you are a perfectionist about fonts there's work to do. I don't know of any program to simplify the job and if I did I wouldn't risk using it — too much could go wrong.

LibreOffice can be built without the bundled fonts. Specify --without-fonts to autogen.sh.
Ed

I neglected to mention that I also did a search for odd interesting or otherwise attractive fonts of the TTF or OTF variety and made a package of those for my own use which I can just dump in. Slackware has no dependency checking or keys, they are just common or garden archives. I have yet to hear of one corrupt package being distributed.

you can just use ~/.fonts

copy some ttf into it.

here some freefonts for play.
https://gitlab.com/openbsd98324/freefonts/

Close libre office, restart it, find and play with new TTF / Fonts.

The problem was not how to add fonts but how to remove them. It can be really annoying with some distros when you're trying to select a font in Writer and you have to scroll down an interminable list.

the fonts are located into /usr/share...

So, the sudo command would be: sudo autogen.sh --without fonts

Generic instructions are here.

Running "apt-get source libreoffice" and "apt-get build-deps libreoffice" should retrieve the necessary files.

You will need to find out the specific build instructions for Mint. Building LibreOffice is relatively straightforward but time-consuming (possibly a few hours).
Ed

And supposing, after waiting for several hours to get a customised LibreOffice, the OP discovers that the fonts are still there — actually provided by Mint? Compiling such a large program on the off-chance that it may solve a problem seems like overkill. I never understood why some distros give you endless fonts for Arabic or Indian languages rather than making them available as optional packages.

I'm not a Debian guy, but maybe something like might show up any installed fonts? There's also the 75dpi & 100dpi fonts that basically nothing uses any more.

Dunno where you got that from; the corrected version is:

EDIT:- Wrong thread...sorry!