are u looking for this 3 words: FTG or just a confirmation that he has a special techinique that was his signature? the word FTG is not mentioned in manga, but in databook probably. probably bcos i cant give u proof, but i think its in databook.
but i can confirm u abt the nature of his signature move that made him famous(if thats what u want proof for)
1. its not common body flicker jutsu, as u said many can do it. its a very advanced time-space (consequently very very fast) jutsu.
You must be registered for see images
2. he was not konoha's 'yellow flash' for nothing. for that time-space jutsu.
You must be registered for see images
3. although u have read it, lets recap.
- 4th gave kakashi kunai
You must be registered for see images
- they
split. 4th to the enemy front line, team kakashi to the bridge
You must be registered for see images
- kakashi is fighting (far away from where 4th is), grabbing special kunai
You must be registered for see images
You must be registered for see images
- so how come 4th arrives in the nick of time and defeated all?
You must be registered for see images
its time-space jutsu, which is why he is called 'yellow flash'.