what was that category in Jeopardy that had answers in a series of numbers?

[CTyankee]

hubby and I couldn't figure it out...

[dem4decades]

1. Decipher Our Top Secret Codes - A1. B2 etc.

[CTyankee]

3. Oh, that's why we couldn't figure it out...

[rsdsharp]

4. Wait til you get your Little Orphan Annie secret decoder ring.

You’ll be a whiz! 👍

[dem4decades]

6. Drink your Ovaltine.

[rsdsharp]

7. I was always a Quick guy,

but I take your point.

[rurallib]

2. something about codes

and the code was letter's number positions in the alphabet

[CTyankee]

5. I get it but it makes my head hurt.