[CONNECT C++] Item Type custom data

An Item Type property can take several data types, including custom...

Data types for CustomProperty::Type: Boolean = 0, DateTime = 1, Double = 2, Integer = 3, Point = 4, String = 5, Custom = 6

Can the custom data type be used to store either an image or a reference to an image?  For example, could a user annotate an object with, say, a photo of the real thing?