The table below shows the correspondence between COM data types and APL arrays.
| OLE DataType | APL array |
| VT_BOOL | numeric scalar |
| VT_I1 | numeric scalar |
| VT_I2 | numeric scalar |
| VT_I4 | numeric scalar |
| VT_R4 | numeric scalar |
| VT_R8 | numeric scalar |
| VT_BSTR | character vector |
| VT_CY | 2-element numeric vector |
| VT_DATE | 6 element numeric vector |
| VT_VARIANT | any array |
| VT_SAFEARRAY | any array (VT_ARRAY OF VT_VARIANT) |
| VT_DISPATCH | ⎕OR of a namespace |
| VT_COLOR | 3-element RGB |
APL vectors may be described by pre-fixing the data type string with 'VT_ARRAY OF '. For example 'VT_ARRAY OF BSTR' specifies a vector of character vectors.
If the APL array is the ⎕OR of a namespace, its data type should be specified as 'VT_DISPATCH'.