Value Display and History problem

I’ve just been trying HISTORY and realised that you have to put numbers in there. If you send “15c” for temperature, the number is not stored - if you send “15” it is - but I can’t find any way in the setup to add “c” or “%” for humidity to the output without disabling the history !! Am I missing something?

We will later modify Value Display Widget and you’ll be able to add prefixes and suffixes in the app.