Some symbols you can use in this forum:
α β γ δ ϵ ε ζ η θ ϑ ι κ ϰ λ μ ν ξ π ϖ ρ ϱ σ τ υ ϕ φ χ ψ ω ϡ Γ Δ Θ Λ Ξ Π Σ Υ Φ Ψ Ω Ϟ Ϡ ∅ ℧ ∏ ∇ ∂ µ ∠ ∡ ℏ Å ℵ ℓ ℋ ℒ ℑ ℜ ℘
If you have some, please post it.