When you choose a font in the Font Preferences, you can find a sample text that displays all the letters of the current system language. In this way, you are able to to have a good understanding of how a font looks like. Such phrases are called Pangrams, meaning contains all the letters. The most common one is that for English, The quick brown fox jumps over a lazy dog. A Greek example is found on the title of this entry.
Is there an alternative for Greek so we can use in FLOSS; The current Greek pangram means
I uncover the soul-destroying abhorrence.