At the beginning of an object file, or immediately after the signature of an image file, there is a standard COFF header of the following format. Note that the Windows NT loader limits the Number of Sections to 96.
| Offset | Size | Field | Description |
| 0 | 2 | Machine | Number identifying type of target machine. See Section 3.3.1, "Machine Types, " for more information. |
| 2 | 2 | NumberOfSections | Number of sections; indicates size of the Section Table, which immediately follows the headers. |
| 4 | 4 | TimeDateStamp | Time and date the file was created. |
| 8 | 4 | PointerToSymbolTable | File offset of the COFF symbol table or 0 if none is present. |
| 12 | 4 | NumberOfSymbols | Number of entries in the symbol table. This data can be used in locating the string table, which immediately follows the symbol table. |
| 16 | 2 | SizeOfOptionalHeader | Size of the optional header, which is required for executable files but not for object files. An object file should have a value of 0 here. The format is described in the section "Optional Header." |
| 18 | 2 | Characteristics | Flags indicating attributes of the file. See Section 3.3.2, "Characteristics," for specific flag values. |