<!-- Translation file for FE -->
<frontend>	     
    <translate>
        <modules>
            <Sheldon_Module>
                <files>
                    <!-- filename under app/locale/LANGUAGE_CODE/ f.e.: LANGUAGE_CODE = "EN_US" -->                    
                    <default>filename.csv</default>
                </files>
            </Sheldon_Module>
        </modules>
    </translate>
</frontend>
 
<!-- Translation file for BE-->	
<adminhtml>	
      <translate>
            <modules>
                <Sheldon_Module>
                    <files>
                        <!-- filename under app/locale/LANGUAGE_CODE/ f.e.: LANGUAGE_CODE = "EN_US" -->
                        <default>filename.csv</default>
                    </files>
                </Sheldon_Module>
            </modules>
        </translate>
</adminhtml>

As you can see, you can use the same file for frontend and backend.