181101, 181103, 260121, 270305, 280105 - Tires, inner tubes, tire marks, snow chains. Shock absorbers, mufflers, tailpipes. Circles that are totally or partially shaded. Representations of objects forming letters or numerals, including punctuation. Inscriptions in Greek characters, including the following: Α α Β β Γ γ Δ δ Ε ε Ζ ζ Η η Θ θ Ι ι Κ κ Λ λ Μ μ Ν ν Ξ ξ Ο ο Π π Ρ ρ ς Σ σ Τ τ Υ υ Φ φ Χ χ Ψ ψ Ω ω.