I would like to know if there is a reliable way to use symbols in meta-description like seen here
http://print24.com/ch-de/product/visitenkarten/
-> go to source-code and see within "meta description" the checkmarks used. Is this only possible with a supported font or would icons (glyphicon, fontawesome) also succeed.
The above example works in google but is there a reliable way to support bing and yahoo too?
                        
A
meta-descriptioncan only contain text.In the example you mentioned, they use
✓, which is just another text character (technically not different toa,1etc.). Unicode defines all these characters. There are, for example, also emoticons likeand.For displaying these characters as intended, your users need to have fonts installed that contain/support them.