/r/plens
Pacific Southwest Airlines (PSA) was a predecessor to US Airways, which has itself merged into American Airlines, but back in the PSA days, they had smiley plens! The legend is that someone in maintenance needed to paint an alignment mark on an aircraft's nose to help them install some radar gear, and it ended up looking like a smiley face. It got massively popular in addition to being adorable; they even used "Catch Our Smile" as a slogan.
Linkzorz:
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Much happy. Very smile. Cool plen iz cool. <3