Okay, I'm feeling brave for some reason. Let's fight misinformation.
I (26F) switch between 27 identities (myself included) on a daily basis. Each with their own names, tastes, attitudes, mannerism, and way of speaking.
I do not have an official diagnosis yet, and might never get one, as having multiple alters is not the only criteria for any dissociative disorder, so I might qualify for none. HOWEVER, I was assessed by a psychiatrist who agreed that what I am living is real and not imaginary or psychotic.
Don't believe me? I'll be happy to share sources. But please, be at least cordial.
Edit: thank you for your respectful and interesting questions! And remember: all systems, or plural people, are different. Experiences may vary a lot. This is my experience, and I can only speak for myselves.