There's an infamous story in music. It's about this:
Van Halen's infamous tour rider from the 1980s contained the immortal line: "M&M's (WARNING: ABSOLUTELY NO BROWN ONES)."
Many have quoted this as a sign of arrogance and excess in rock. But there's perhaps a different reason; a very smart piece of small thinking. Van Halen were the first major act to really tour secondary and tertiary markets in the US and were unsure about how good and safe the venue organizers were there. If they got to the venue and found Brown M&Ms they could deduce either the rider hadn't been read carefully or was being ignored. And this means the more important aspects of staging - lighting, safety, sound, security - could have been screwed up by an amateur (or arguably criminal) promoter. It was the proverbial canary in the coal mine. It was a brilliant bit of thinking small.