That is most likely your choices "name". S123 database likes to store items as names rather than labels. If you made your survey in the Web App, I am not sure if you can even change a choice's name, so those may be the default if that is the case.
I find creating meaningful names is helpful, and tend to abide by these rules:
- Letters, numbers, and underscores only
- No spaces
- Short descriptive text that relates to the choice being made
- Never use meaningless codes that need to be deciphered (ironic example being "choice1")
Technically select_one can have spaces in the name, but select_multiple can't. I prefer consistency. And some of my label are rather large, so I don't bother with 1:1.