A hybrid-capability system in one in which access is allowed only if it satisfies both ObjectCapabilityModel rules and AccessControlList rules.
The IBM System/38, now known as the AS/400, has two kinds of capabilities: normal object-capabilities and so-called "unauthorized capabilities". For the latter, access also carries a principle-ID, and is allowed only if the AccessControlList mechanism says it's ok.
Hybrid-capability systems include
CategorySecurity CategorySecurityModel CapabilitySecurityModel