RE: opt-in opt-out

at simply secure residency we each had a name badge on

• Name
• pronoun
• socials
• green sticker if you opted-in to being in photos. so if someone did not have a green sticker on them then you were to assume they didn't cosent to photos...

There was also chattam house rules

Chatham House Rule
/ˌtʃatəm haʊs ˈruːl/Submit
nounBRITISH
plural noun: Chatham House Rules
a rule or principle according to which information disclosed during a meeting may be reported by those present, but the source of that information may not be explicitly or implicitly identified.
"the conference was held under the Chatham House Rule"