I am often asked about the title 'Soke' and its meaning...
It really should be written as 'Souke' or 'Sōke' as the 'o' is a Japanese long vowel.
Sou 宗 シュウ ソウ むね かず し そ そお たか とし のり ひろ むな もと よし origin; essence.
Ke 家 カ ケ いえ や うち あり え く つか べ house; home.
The kanji gives the idea that the 'Sōke' comes from the origin of the house. Meaning that the 'Sōke' comes from the 'origin' or founder of the system. Normally, this title is used to indicate who is currently head of a ryu, ryu-ha or art when the founder of the ryu, ryu-ha or art has passed away.
It has been very badly used and misrepresented for many years in the west mainly by those who do not know its original usage, they simply see it as 'another' high level title to use.
One should not really use such a title if the founder of their ryu, ryu-ha or art was still alive, but having said this, we should note there are not really any of the original founders of arts left alive today.
It should be noted that in Japan/Okinawa, the title would only be used by the son/daughter of a founder, or the nominated inheritor. Obviously, if the son or daughter did not want to take on such a daunting task, then an inheritor would normally be appointed by the seniors of the ryu.
If someone in the west chooses to use the title in a different manner, it is not wrong, simply different, and should be noted as such. All too often I read articles and comments where the writer assumes a 'holier than thou' approach because they belong to this group, or that group - thinking that their group is better than yours because of some odd reason. There is no right, there never was, it is about being the best you can be for you... And, that does not include having a 'better' title than the guy in the next block, OR criticising him/her because they use that title and you do not.
It is after all better to find the similarities in what we all do, rather than argue about what we do that's different....?
[It should be noted that I do not use the title Sōke - now - or never have done, and never will, or can as I am 開祖 the first generation founder of a ryu].