It was common belief (at least amongst us non-Korean stylists) that TSD and TKD were two distinct styles.
I am korean stylist and that is not shared by me. TaeKwonDo was a name change to Tang Soo Do schools, with replaced katas.
These techniques are 99% identical to the ITF TaeKwonDo branch, with some very, very minor exception (crescent kick with leg straight rather than bent).
If you want to distingush arts from each other based on an innoccious crescent kick difference, be my guest..