Says who? The Corduroy Appreciation Club. Yes, it exists. But why did they choose to celebrate on 11-11-11? Because the elevens comprising this date most closely resemble the texture of Corduroy fabric.
Another point of interest is the CAC’s main public symbol, the whale. Whale is a homonym of wale, which is the name for the raised portion of Corduroy—the fabric's most distinctive trait.
Wow, hard core.