California Proposition 63 may refer to: California Proposition 63 (1986) - Official State Language. Initiative Constitutional Amendment California Proposition 63 (2004) - California Mental Health Services Act (MHSA) California Proposition 63 (2016) - Firearms and Ammunition Sales This disambiguation page lists articles associated with the title California Proposition 63.If an internal link led you here, you may wish to change the link to point directly to the intended article. Wikiwand - on Seamless Wikipedia browsing. On steroids.