The Type field of a symbol table entry contains two bytes, each byte representing type information. The least-significant byte represents simple (base) data type, and the most-significant byte represents complex type, if any:
| MSB | LSB |
| Complex type: none, pointer, function, array. | Base type: integer, floating-point, etc. |
The following values are defined for base type, although Microsoft tools generally do not use this field, setting the least-significant byte to 0. Instead, CodeView information is used to indicate types. However, the possible COFF values are listed here for completeness.
| Constant | Value | Description |
| IMAGE_SYM_TYPE_NULL | 0 | No type information or unknown base type. Microsoft tools use this setting. |
| IMAGE_SYM_TYPE_VOID | 1 | No valid type; used with void pointers and functions. |
| IMAGE_SYM_TYPE_CHAR | 2 | Character (signed byte). |
| IMAGE_SYM_TYPE_SHORT | 3 | Two-byte signed integer. |
| IMAGE_SYM_TYPE_INT | 4 | Natural integer type (normally four bytes in Windows NT). |
| IMAGE_SYM_TYPE_LONG | 5 | Four-byte signed integer. |
| IMAGE_SYM_TYPE_FLOAT | 6 | Four-byte floating-point number. |
| IMAGE_SYM_TYPE_DOUBLE | 7 | Eight-byte floating-point number. |
| IMAGE_SYM_TYPE_STRUCT | 8 | Structure. |
| IMAGE_SYM_TYPE_UNION | 9 | Union. |
| IMAGE_SYM_TYPE_ENUM | 10 | Enumerated type. |
| IMAGE_SYM_TYPE_MOE | 11 | Member of enumeration (a specific value). |
| IMAGE_SYM_TYPE_BYTE | 12 | Byte; unsigned one-byte integer. |
| IMAGE_SYM_TYPE_WORD | 13 | Word; unsigned two-byte integer. |
| IMAGE_SYM_TYPE_UINT | 14 | Unsigned integer of natural size (normally, four bytes). |
| IMAGE_SYM_TYPE_DWORD | 15 | Unsigned four-byte integer. |
The most significant byte specifies whether the symbol is a pointer to, function returning, or array of the base type specified in the least significant byte. Microsoft tools use this field only to indicate whether or not the symbol is a function, so that the only two resulting values are 0x0 and 0x20 for the Type field. However, other tools can use this field to communicate more information.
It is very important to specify the function attribute correctly. This information is required for incremental linking to work correctly. For some architectures the information may be required for other purposes.
| Constant | Value | Description |
| IMAGE_SYM_DTYPE_NULL | 0 | No derived type; the symbol is a simple scalar variable. |
| IMAGE_SYM_DTYPE_POINTER | 1 | Pointer to base type. |
| IMAGE_SYM_DTYPE_FUNCTION | 2 | Function returning base type. |
| IMAGE_SYM_DTYPE_ARRAY | 3 | Array of base type. |