Error 0x80042603

Value: -2147211773 | 0x80042603 | 2147755523

What does it mean ?

NOTESPH_E_UNSUPPORTED_CONTENT_FIELD_TYPE  
Only rich text, HTML, and text types are supported for the content field.
Value: 9731 | 0x2603 | 0b0010011000000011

Where does it come from ?

FACILITY_ITF  
COM/OLE Interface management. FACILITY_ITF is designated for user-defined error codes returned from interface methods
Value: 4 | 0x004 | 0b00000100

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