Yes I totaly agree, I need to add something to comply with this as I'm in the UK (my bad), even tho I think it's stupid and may never get enforced.
I can't afford the legal costs if it ever did and as a community/open source project I'm just informing the rest of the community who may or may not be aware of this, as I didn't find it mentioned before.
@betro-hakala I don't even know what you want to be transparent. Also, if you are using Vanilla theme (not Persona) then the theme's options won't be in NodeBB Category options, those are completely different.
Could you send a screenshot of what you want transparent? That would help us help you.