Which limits on firearm possession did the Supreme Court say were not questioned by District of Columbia v. Heller?

In the landmark case District of Columbia v. Heller (2008), the U.S. Supreme Court established that the Second Amendment protects an individual's right to possess firearms for traditionally lawful purposes, such as self-defense within the home.12

However, the Court explicitly clarified that this right is not unlimited. In the majority opinion, the Court noted that its decision did not cast doubt on longstanding regulatory measures, including:2

• Prohibitions on the possession of firearms by felons and the mentally ill.1
• Laws forbidding the carrying of firearms in sensitive places such as schools and government buildings.1
• Laws imposing conditions and qualifications on the commercial sale of arms.1

The Court further emphasized that the Second Amendment does not protect the right of citizens to carry arms for any type of confrontation, drawing a parallel to how the First Amendment does not protect the right to speak for any purpose.2