The SubDomainCommunicationMode enumeration defines the possible values for the SubDomainCommunication property of the IHtml5SecuritySettings interface.
Possible values are:
SDCM_DISABLED: Sub-domain communication is always disabled.
SDCM_OPTIONAL: Allows communication if the presentation was opened with the enableSubdomainCommunication=1 parameter.
SDCM_ENABLED: Sub-domain communication is always allowed.