Yes, they are referred to that way (in our kwan at least, and I think it's pretty common across kwans and arts).
The only "exception" would be 1st dan, which we call Cho dan more commonly than Il dan. One of our Korean instructors told me that the term "Chodan" has a Chinese origin.
LF, can you explain the Il dan / Cho dan distinction?
I will try!
Also, I invite others who know the etymology better than I to join in.
Yes, Iceman, it does go as you guessed!
1st Degree 일단 Il Dan
2nd Degree 이단 Yi Dan (or Ee Dan)
3rd Degree 삼단 Sam Dan
4th Degree 사단 Sa Dan
5th Degree 오단 Oh Dan
6th Degree 육단 Yuk Dan
7th Degree 칠단 Chil Dan
8th Degree 팔단 Pal Dan
9th Degree 구단 Gu Dan
[The honorary
10th Degree is Sip Dan 십단 - pronounced like "sheep Dahn"]
(spelling variations occur due to early phonetic interpretations)
Many schools do still use the "Cho Dan"
초단 which is accurate, but not really in the same sequence as numbering "1st through 9th." The Korean word "Cho" probably has Chinese origins, but is used in many Hangeukmal words. It means "the beginning" or "early stage" of something.
Here are some examples from Dong-Ah's Dictionary:
초가을 Cho Ka Eul - Early Autumn; the beginning of Fall. (Harvest time)
초고 Cho Ko - A rough copy; a draft
초기 Cho Ki - The early days [period]; the first stage; an early stage.
초대 Cho Dae - The first generation; the founder; the originator
초등 Cho Deung - Elementary; Primary
초보 Cho Bo - The first steps; the first stage; elements; rudiments; the beginning; the start.
Also as in
기초 "
Ki Cho" - Base or foundation - like in
Kicho form.
초단 Cho Dan - can mean the "first grade" which means the first level, or beginning stages of the Black Belt.
The rank itself is called "IL DAN."
Here's a funny little story about the term "Shodan vs. Chodan." When I was about to become a 1st Degree Black Belt in 1978, I was talking to a special advisor in the ATA who was filling us in on the terminology. Many instructors had requested English words to be embroidered on their Black Belt such as "1st Degree." This advisor had said that the correct term was "Shodan" which meant "First Degree" (as it turns out that is the Japanese term). When my instructor asked me what I wanted embroidered on my new Black Belt, I said "Shodan." I still have this belt today.
A short while later, I was attending a testing in Lansing, Michigan, at the headquarters school of the highest ranking American in the ATA at that time, 5th Dan, ATA Vice-President Robert Allemier (He is currently ATA Chief Master, 8th Dan and is in Texas). During the after hours socializing, I was standing next to ATA Founder, 9th Dan GM H.U. Lee. After a while of conversing, he looked down at my belt and said in a thick Korean accent, "Sho Dan, is that your name?" I looked at him rather puzzled wondering why a Korean did not recognize his own language. I replied, "No sir, it's my rank," to which he nodded and acknowledged with a polite "Oh, I see."
I think that many Korean Taekwondo schools, following the end of the Japanese occupation in 1945 (some of which also taught Yudo as a grappling comparison to Judo), used the Korean term "Cho Dan" because it is similar sounding to the Japanese "Sho Dan" which means "First Degree."
CM D.J. Eisenhart