The first line of any spec file must contain the Origin: keyword. For describing IDL source files to CORBA projects, the value of this keyword must be OMG-IDL. Thus the first line of a spec file for IDL must be:
Origin: OMG-IDL
Also required in the header of this kind of spec file is the keyword IDL-file:, with a value that is a pathname for the IDL file that is to be compiled. The pathname is interpreted relative to the folder containing the spec file. As noted in Section 7.4.1, the folder containing the IDL file will be used to store any projects generated automatically from the IDL.
Note that a spec file can describe only one IDL file. However, projects can contain more than one spec file.
For example, this is the minimum spec file for describing an IDL file called bank.idl that is in the folder bank, a sibling folder of the folder containing the spec file.
Origin: OMG-IDL IDL-file: ..\bank\bank.idl