User blog:Cyan Wind/Challenge Patches surprised me... o.O

I decided to sneak around several *cough* a lot of *cough* profiles last night and I could see a lot of special badges. Moreover, lots of retired badges of Khan Academy surprised me. That made me wonder "Did they come up with a badge, create it and then make it old or something?".

You must have seen a badge like this: Chemistry (old). Wait! There is another badge: Chemistry. KA created a deprecated badge like this: Percents (deprecated). Oh, how about adding the word old? Tah dah ~ Percents (deprecated) (old)

As you know, I am trying to elaborate badges & badges categories. Well, thanks for giving me more work, Khan Academy!

However, from what I have collected, I am pretty sure that Atlas is about mastering unique skills. There are some particular badges. They are refurbished but they are not Challenge Patches: There is not Da Vinci (old) for achieving proficiency in 500 skills. Wait... I forgot to list a badge, which is not a Challenge Patch but has newer version: Atlas (old).
 * Work Horse (old) - Achieve proficiency in any 50 skills
 * Magellan (old) - Achieve proficiency in any 100 skills
 * Copernicus (old) - Achieve proficiency in any 200 skills
 * Kepler (old) - Achieve proficiency in any 300 skills
 * Newton (old) - Achieve proficiency in any 400 skills

Here is my assumption: Atlas (old) - Achieve proficiency in any 500 skills. Its newer version (Atlas) maybe available to earn for mastering 1000 unique skills.