Although most types defined in MFR Library API are self-explanatory, some are vague.
Clarification on some of those vague API's are given below:

mfrSERIALIZED_TYPE_MANUFACTUREROUI /**< Manufacturer OUI. */
ManufacturerOUI - Organizationally unique identifier of the associated Internet Gateway Device.

mfrSERIALIZED_TYPE_PRODUCTCLASS /**< Product class. */
ProductClass - Identifier of the product class of the associated Internet Gateway Device.

mfrSERIALIZED_TYPE_SERIALNUMBER
SerialNumber - Serial number of the associated Internet Gateway Device

mfrSERIALIZED_TYPE_PROVISIONINGCODE /**< ACS provisioning code. */
Provisioning Code - ACS (auto configuration server) provisioning code, All communications and operations b/n the CPE and ACS are performed in the scope of the provisioning session.

mfrSERIALIZED_TYPE_VENDOR_CONFIGFILE_ENTRIES /**< Vendor ConfigFile entries. */
Vendor config file - Currently not used, it used to represent the vendor configuration details of the box.

mfrSERIALIZED_TYPE_VENDOR_LOGFILE_ENTRIES /**< Vendor LogFile entries. */
Vendor log file - It represents the logs available from the /opt/logs. Not supported as of now. Initially there was a plan to represent the RDK logs but it is not implemented.

mfrSERIALIZED_TYPE_SUPPORTED_DATAMODEL_ENTRIES /**< Supported DataModel entries. */
DataModel: A well defined hierarchical structure wherein most of the configuration and diagnostics are performed through setting and retrieving the value of the device parameters. This structure is more or less common to all device models and manufacturers

mfrSERIALIZED_TYPE_PROCESSOR_ENTRIES /**< Processor entries. */
Processor entries - It is used to get the details of number of processes that are active. It gives the nunber of processors available in the box.