More and more recently I see empty rectangles in text areas on the web. I think it is Ubuntu 14.04's character encoding/Unicode libraries not being up to date but I don't know. I also think it is mostly emoji but cannot actually see the characters to know for sure.
How can I fix this?
The webpages do have a <meta charset="UTF-8"> in them.
UPDATE: Here is the webpage, https://docs.amazee.io/changelog.html.
I see those 3 characters in Android devices. The "running man", up symbol, and bicep muscle. Follow the link @xhienne refers to by listing chars, then click on "fonts that support". Seems certain you need an emoji font. Look at the display on one of your mystery characters: http://www.fileformat.info/info/unicode/char/1f199/fontsupport.htm
This is just a font problem. None of the fonts installed on your system include the three Unicode characters after "with a" (*). As a fallback, rectangles are drawn instead.
The solution is to install the right font. I can't recommand one since no one font can cover the whole Unicode set (which is huuuuge).
(*) On this webpage, they are U+1F3C3, U+1F199 and [U+1F4AA][4]
[update following @wjandrea's comment] Ubuntu provides support for those characters with package ttf-ancient-fonts. To install it type this command:
apt-get install ttf-ancient-fonts
