Is there an official English transcription/translation? Post in other languages are usually ignored or flagged. (I think the videos in YouTube have automatic subtitles and it's possible to use automatic translation, but for now a manual version is better.)
When it's an event covered by different sources, it's better to find a version in English.
When there is an official translation, it's better to post the translation.
But sometimes there is no English equivalent :(
I remember very few post that got traction in other languages, like "Homer in CSS" in Spanish, or a very strange custom keyboard in Japanese. It has to be very unusual, extremely good and have a strong visual component.
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From and old comment by dang:
> We have deep respect for other languages but HN is an English language site, so the articles posted here need to be in English.