I began using the title of "Sabeom" or "Master" in 1987 when the Korean Master with whom I was training told me I was a "Master" and should use the title. I opened my first Dojang in 1978. By 1985, I was 4th Dan and had been teaching for 7 years, but had not known of the proper titles. I believe it is proper to use the term Sabeom whenever your Master, or Grandmaster who teaches you, awards you the title.
I'm not always 100% current on everything, so correct me if I'm wrong, but the WTF has nothing to do with ranks (anymore), or Dan promotions, and there is no mention on their website that I know which indicates any required levels of "Master" titles.
From WTF.org
"The WTF, an international sports federation governing Taekwondo, is mainly handling affairs related to member national associations and pertinent international Taekwondo competitions. There is no private dojang, a teaching institutes, whatsoever directly affiliated with WTF in any form. So, it is not relevant to ask anything about information regarding private dojangs to WTF."
"All matters about black belt Poom/Dan certification are dealt with by the Kukkiwon (World Taekwondo Headquarters). Dan/Poom promotion tests are conducted according to the Regulations for Promotion Tests of the Kukkiwon."
As for the Kukkiwon, their site contains Dan testing requirements, but makes no reference to anything to do with Master titles except in one passage about "High Dan Testings" 8th and 9th Dan, pertaining to recommendation by a "Taekwondo master holding 9th Dan or higher..."
"11. Submit documents
a. One application form for promotion test
b. Apply to 8th, 9th Dan with application recommendation by a Taekwondo master holding 9th Dan or higher or president of the member national association of the WTF in the pertinent country
c. Curriculum vitae that includes the martial arts career
d. Foreigners of Korean origin should submit a document that certifies his/her residence outside Korea."
It is my understanding that the English term of "Master," and the Korean term of Sabeom ( 사범 ) are Kwan terms which vary from Kwan to Kwan, and organization to organization. In general terms, "Sabeom" refers to anyone who is designated by a Kwan leader (the Kwanjangnim - 관장님 to be a teacher of Black Belts (usually a 4th or 5th Dan)
The specific title of Sabeomnim ( 사범님 ) is reserved only for the one person who is in charge of a Dojang - - the school head (owner) or "head master" (In Korea, it was usually required to be 6th Dan for this). This is sometimes referred to as a "Chief Master," "Senior Master," or even a "Senior Instructor." This is the one top dog at any particular school.
Other instructors within the school might be awarded the title of a Master, and be called a "Sabeom" in accordance with their rank, but there is only one "Sabeom of the Dojang." I believe that traditionally in Korean Taekwondo, only one person within each school is called the Sabeom, but the term "Master" has taken on a wider definition.
Sabeom ( 사범 ) means "Master" or "Head Teacher."
honorific form is Sabeomnim
Kyo sa ( 교사 ) means a "teacher; instructor; schoolteacher."
honorific form is Kyosanim.
Jo kyo ( 조교 ) means an "assistant."
honorific form is Jokyonim.
My experience in the Army was similar. There are many Generals, each with different designation depending on the number of stars.
1 star = Brigadier General
2 star = Major General
3 star = Lieutenant General
4 star = General
5 star = The President (The last 5 star Army General Dwight D. Eisenhower)
They are all called "Generals," but there is also a difference in rank and specific titles.
At basic training we had the rank of E-5 sergeants who were not "Drill Sergeants." There were several E-5 and E-6 who were Drill Sergeants (DS), but only one was the "Senior Drill Sergeant" (SDS), and he was in charge of the other Drill Sergeants for each of the three platoons in Delta Battery.
As to consideration for any Taekwondo Master Instructor who has one of their students promoted to the rank of Master, it is not a threat to their status, but a badge of honor that they have one or more students whom they have trained to this high level.
CM D.J. Eisenhart
It seems to me that (as we can see from the posts here) that titles (Kyo Sa, Sabom, etc) tend to take on their own meaning in different schools. I've certainly heard enough stories of Korean insructors saying, "Master is 4th Dan." Then a student gets close to that & the instructor says, "Master is 5th Dan."
CM Eisenhart, It seems as though "Army General" meaning different things depending on which base your in. No wonder it seems to mean less to people in MA all the time.