What signifies the difference between a positive and neutral effect on the turnover?

From the Oracle documentation, "JDEdwards Enterprise One Applications Human Capital Management Implementation Guide", section 27.1.3 describes the importance of an alpha change reason and a numeric change reason.  The alpha change reason will have a negative [-] impact on the turnover while the numeric has either a positive [+] or a neutral [0] effect.  What the document does not detail is what differentiates a positive [+] from a neutral [0] within a numeric change code.

We have a number of changes (ie 050) that signify a database correction.  Sometimes these have a positive turnover net effect and sometimes they have neutral net effect.  How would we default one versus the other?