String 

IFILE = parameter_file_name 

Static 

None 

Valid parameter filenames 

Multiple instances can have different values. 

Use IFILE to embed another parameter file within the current parameter file. For example:

IFILE = COMMON.ORA

You can have up to three levels of nesting. In this example, the file COMMON.ORA could contain a second IFILE parameter for the file COMMON2.ORA, which could contain a third IFILE parameter for the file GCPARMS.ORA. You can also include multiple parameter files in one parameter file by listing IFILE several times with different values:

IFILE = DBPARMS.ORA
IFILE = GCPARMS.ORA
IFILE = LOGPARMS.ORA

You must list multiple entries on contiguous lines of the parameter file.