[ssiewk]

Why doesn't spell check pick up TH as a misspelled word. I have removed the check to ignore uppercase errors

 

[AlbertMC2]

Hi

Because it is a valid abbreviation.
Among other possibilities TH is the abbreviation for Terahenrys
Tera (Capital T) = 10^12 (10 to the power of 12)
Henry (Capital H) = SI unit for the measurement of Electrical Inductance