Where is the format spec for release version object file?

[alanccw]

I try to use this document https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#coff-file-header-object-and-image

This spec works for debug version (Generated by VC++ 2008) object files. But not work for the release version.

I find the release version has an extra header with 6 bytes 00 00 FF FF 01 00, then followed by the target machine type(2 bytes), then the following 2 bytes are not the correct number of sections. So I think this is a separate spec for release version of .OBJ file, not follow or partially follow the COFF spec