Please clarify the "etiquette" speaking in english

[PioPio]

Also, should we apply the same rules to voice chat during events?

I'm pretty sure voice chat during events is entirely up to the house members, as it is their own event and people outside of the house are just guests. Some houses also use their own teamspeak servers or even discord, so I won't see how NI rules would apply there.
I'm against holding conversations in other languages (than english) on the official servers, because it makes the communication unclear for most of our multicultural community members. As Kaasovic said you can use a lot of other platforms, we do have an official teamspeak server with public channels that everyone is free to use.