# D0 CF 11 E0 A1 B1 1A E1 — File format magic numbers For D0 CF 11 E0 A1 B1 1A E1, offset is 0; extension is doc xls ppt msi msg; format is Compound File Binary Format , a container format defined by Microsoft COM. It can contain the equivalent of files and directories. It is used by Windows Installer and for documents in older versions of Microsoft Office . [ 44 ] It can be used by other programs as well that rely on the COM and OLE API's. ( 0xD0CF11E0 visually resembles "DOCFILE". [ 45 ] ), recorded from its source on 2026-08-03. - **Hex signature:** D0 CF 11 E0 A1 B1 1A E1 _(unconfirmed — we could not tie this to the quote below)_ - **Offset:** 0 _(unconfirmed — we could not tie this to the quote below)_ - **Extension:** doc xls ppt msi msg - **Format:** Compound File Binary Format , a container format defined by Microsoft COM. It can contain the equivalent of files and directories. It is used by Windows Installer and for documents in older versions of Microsoft Office . [ 44 ] It can be used by other programs as well that rely on the COM and OLE API's. ( 0xD0CF11E0 visually resembles "DOCFILE". [ 45 ] ) ## What the source says > doc xls ppt msi msg | Compound File Binary Format , a container format defined by Microsoft COM. It can contain the equivalent of files and directories. It is used by Windows Installer and for documents in older versions of Microsoft Office . [ 44 ] It can be used by other programs as well that rely on the COM and OLE API's. ( 0xD0CF11E0 visually resembles "DOCFILE". [ 45 ] ) ## Source - https://en.wikipedia.org/wiki/List_of_file_signatures Last verified: 2026-08-03. Review by: 2027-08-03. Part of [File format magic numbers](https://referencesource.org/file-format-signatures/).