MediaWiki:Apihelp-query+userinfo-paramvalue-prop-cancreateaccount
Indicates whether the user is allowed to create accounts. To check whether some specific account can be created, use action=query&list=users&usprop=cancreate.
Indicates whether the user is allowed to create accounts. To check whether some specific account can be created, use action=query&list=users&usprop=cancreate.