It can display ₐ₊₋ but some other subscripts (like ₂ₙ) are converted to squares. When I copy that square and paste on here the problem disappears: ₂. Why is that? The file is encoded in UTF-8.
Why does Notepad++ display some Unicode characters as square
notepadspecial charactersunicodeutf-8
Related Solutions
Are you sure the characters are in the font?
Browsers search other fonts to find missing characters - therefor you cant use browsers to test font contents.
You can't trust applications either - here I am using an Arabic font in Notepad to show Chinese characters that I strongly suspect are not in the Arabic font. It seems to me the application (or the underlying Windows libraries) are searching other fonts to provide the missing character.
If you need an independent corroboration, you could try FontForge or another third-party font tool.
In MS Word, place the cursor right after a character and enter Alt X (i.e., press the X key while having the Alt key pressed down). In any reasonably modern version of Word, this turns the character to its Unicode code number. To get the name, you can then visit http://www.unicode.org or use Character Map program in Windows, for example. Or you could install BabelPad, a great Unicode editor which shows the Unicode number and Unicode name of each character as you move the cursor right before it.
Alternative, for more fun maybe, you can use http://shapecatcher.com/ and draw the character. For simple patterns, it is rather effective. It immediately recognized that your first character is “White square with upper right quadrant” U+25F3, from my rather clumsy drawing.
Best Answer
It depends on whether the font you use has these symbols defined or not.
I found a basic way to change the font here:
When I pick a font from the list, it is applied immediately, so it's easy to see which one supports characters you need. Of course if you use more than "Global Styles" / "Default Style" then you should modify the above solution accordingly.