Whenever I had to enter resistance I would use Greek capital letter omega (Ω, U+03A9). It is how I was thought since high school and I never questioned it. That is until I accidentally saw that there is an actual ohm sign (Ω, U+2126). All these years I was doing it wrong. Or did I?
Unicode is known for lot of things but logic is not one of them. Although special ohm sign is available and it is clearly named as such, its use is not encouraged. To quote:
The ohm sign is canonically equivalent to the capital omega, and normalization would remove any distinction. Its use is therefore discouraged in favor of capital omega.
In other words: We created special character but we changed our minds since. Please do not use it.
Well, aside for awareness of this Unicode curiosity, I gained absolutely nothing. Omega I used before and omega I shall continue to use.
Long live 42 Ω.