Use Esperanto when no translation

By the way I just compared the io and eo strings and found that about 10 % of the io messages are identical to that of Esperanto. 97 % of the messages translated in io are available in eo.

There are sometimes small differences in diacritics and similar, for instance linguo vs. lingvo or autoro vs. aŭtoro, which should not impair understanding, and some mere differences in lexical choice, like licenza vs. permeso.

Some of the io strings which differ most from eo seem to be in Italian, actually (e.g. «Puoi scegliere la licenza che preferisci»).

In Esperanto, at least according to PIV, you actually can use licenc/o, which is also worded as "permis-il/o".