Since this is an electronics forum, we are going to need to use a bunch of special symbols, such as
µ for (micro), as in µF - micro Farad or
± for denoting a tolerance or degree sign
° as in 20°C
So, I've found and installed this forum extension called Special Characters and Symbols Insertion (let's call it SCSI

) by Chas Large. I would add some functionality to it, such as an Omega sign
Ω for Ohms or
Π - Pi , and I have a feeling Sigma
Σ and Delta
Δ might also be needed

. I'll see if I can whip up (or find) another similar extension for other, scientific or electronics characters.