Hi @MuratKaribay, thanks for taking the time to report this!

How and where to see the problem? Which browsers or operating system does this require?

Also, the attachment here called "Qazaq Tote Jaziwi.rar" includes several fonts. Where are these fonts from? Who created them? Under which license?

Hi @Aklapper, thanks for answering.
This problem was told to me by Kazakhs from China who live in Kazakhstan and they told me that the font used in kk-Arab Wikipedia does not match the style of the Kazakh language (Arabic script). And I studied this alphabet(script) and realized that it really does not fit and looks very ugly. The font was thrown to me by the Kazakhs of China, I don't know who the author is and I don't know if there is a license. The name of the archive "Qazaq Tote Jaziwi" means Arabic script of the Kazakh language. If these fonts do not fit you can use Uyghur fonts like on this page https://ug.wikipedia.org/wiki/ئۇيغۇر_تىلى

The font was thrown to me by the Kazakhs of China, I don't know who the author is and I don't know if there is a license.

The license must be known and it must be open and free. See https://www.mediawiki.org/wiki/Universal_Language_Selector/WebFonts#Selection_of_fonts

In T255300#6221692, @Aklapper wrote:

The font was thrown to me by the Kazakhs of China, I don't know who the author is and I don't know if there is a license.

The license must be known and it must be open and free. See https://www.mediawiki.org/wiki/Universal_Language_Selector/WebFonts#Selection_of_fonts

The desired font is not in the list. Now what would I add a font to where I need to write?

Someone would first need to find a font which has an acceptable license.

Hello @Aklapper, can I see a list of all fonts that can be used in Wikipedia?
Look at this page of the Uyghur Wikipedia https://ug.wikipedia.org/wiki/%D8%A6%DB%87%D9%8A%D8%BA%DB%87%D8%B1_%D8%AA%D9%89%D9%84%D9%89
Can I use fonts like in Uyghur Wikipedia "ALKATIP", "UKIJ Tuz", "ALKATIP Tor", "UKIJ Tor", "UKIJ inchike", "Alpida_Unicode System", "UKIJ Tuz Tom" for kk-arab Wikipedia?

In T255300#6299681, @MuratKaribay wrote:

Hello @Aklapper, can I see a list of all fonts that can be used in Wikipedia?

I guess you'd need to check all fonts which are available as Debian packages, as the Wikimedia servers run on Debian.

Can I use fonts like in Uyghur Wikipedia "ALKATIP", "UKIJ Tuz", "ALKATIP Tor", "UKIJ Tor", "UKIJ inchike", "Alpida_Unicode System", "UKIJ Tuz Tom" for kk-arab Wikipedia?

No idea - you need to find out the license of each of these fonts.
(You're basically asking "Can I copy this image to Wikimedia Commons?" and I reply "You need to tell me about the license of that image first.")

No idea - you need to find out the license of each of these fonts.

Here is a link to UKIJ fonts http://ukij.org/fonts/. LGPL and OFL licenses. The font Creator doesn't respond to emails. Can they be used?

OFL (listed on the website) should be fine. "LGPL" would also be fine but the website does not say which LGPL version so that's broken. http://www.ukij.org/fonts/fonts/UKIJTuz.ttf is the only font I can find on that website. That font says Free distributed and all rights reserved. in the font file itself though.
I don't know if TTF file format from 2004 is still technically sufficient though.

I don't know if TTF file format from 2004 is still technically sufficient though.

And now if the font Creator doesn't respond what should I do?
Can I use UKIJ Tuz?
Or do I need to format it for woff and woff2?

I don't know myself, sorry. Best to ask the Language-Team. See https://www.mediawiki.org/wiki/Wikimedia_Language_engineering#Contact_us for contact info.