User blog comment:KidVegeta/Canonicity/@comment-3097771-20140408221339

Dragon Ball Minus - This is the added volume of Jaco the Galactic Patrolman. It's utterly non-canon. Reasons are as follows:
 * Vegeta is seen training with Raditz. This is a contradiction for numerous reasons on its own. For one, Vegeta is much stronger than Raditz, so using him would be pointless. For another reason, Raditz is a low-class Saiyan. Vegeta is a Super Elite. Vegeta wouldn't associate with a random low-class Saiyan (as explained numerous times throughout DBZ by Vegeta himself).
 * Goku is 3 years old in this story. In all other media, Goku is born right around when Planet Vegeta is destroyed.
 * Bardock gets a message from Frieza to return to Planet Vegeta, which does not occur in his anime appearance in Bardock: The Father of Goku.
 * Bardock is with a random Saiyan when he gets Frieza's message in DBM. This contradicts Bardock's previous appearances, where he was with his team (Tora, etc). In canon, they were killed by Dodoria's Elite, however. Then Bardock was attacked by Dodoria's Elite (alone) before going back to Planet Vegeta of his own accord, so this random Saiyan being around at all breaks canon completely.
 * Bardock never say Goku in canon. In this story, he sees Goku and even talks to him before sending him off. Once again, this breaks canon.
 * Bardock doesn't go challenge Frieza after returning to Planet Vegeta, which breaks canon.

A few more notes: I know this was written by Toriyama, and what he says should be the "highest" canon. However, this special contradicts numerous things which Toriyama himself wrote years back with the original manga, including very important things like Goku's birth year (thus, his age), and even Saiyan culture (low-class and elites not mingling, etc). Because Toriyama is contradicting himself in this instance, this manga cannot be canon.

Overall, a very disappointing new story from Akira Toriyama. I expected better. He should know his own universe. He's really become an embarrassment and a hack. -KidVegeta (talk)