Stigmas
one common stigma is that people with DID will use "oh another Alter did it" as an excuse, when that's not entirely true, in fact that can be a sign of the person attempting to imitate or "fake" DID. if you have DID you need to have what's called System Responsibility, which is if a member of your system causes harm, or does something wrong, your system needs to fix it, and put things as right as you can, and not doing so is not only disrespectful to those around you, but also paints your system in a bad light. if someone does this, try saying "hey, you should have System Responsibility and try to put this right" and let the system try to make amends, or remove the system from your life.
another common stigma is that all systems are faking it, or that systems don't exist, however this is not true, DID is a real disorder, and science has proven this as brain scans show changes in brain activity depending on who is fronting at that moment, and as for seeing so many systems, statistics show that there's not more people with DID than there should be statistically, and easy math will show this.