Oracle Import Export compatibility matrix

Is there an official matrix that clearly explain how export dump format done with a specific version, is or not compatible with all others?

I mean to fill this grid:

Exp done with version:     | 7  | 8i | 9i | 10g | 11g
Is compatible with Imp   7 |yes | no | no | no  | no 
                         8i|yes |yes | no | no  | no 
                         9i|yes |yes |yes | no  | no 
                        10g|yes |yes |yes | yes | no 
                        11g|yes |yes |yes开发者_如何学C | yes | yes 

I known there are many specific thinks between YES and NO.

I also need an Oracle official clear sentence like this: "Oracle will allways support back-ward compatibility for import any old export dump format"

please help me

Metalink 132904.1 Compatibility Matrix for Export and Import Between Different Oracle Versions is the document you're looking for.

I doubt that Oracle has ever made a commitment that something will always be supported. For example, the regular export command is being desupported in 11g in favor of the DataPump version, which uses a different file format. The old export utility will be around for a while, but I wouldn't assume that 10 releases down the line Oracle would even be shipping versions of the non-DataPump export and import utilities.