What the next identification paper must supply

The supplied XVI-D record keeps inherited coordinate compatibility conditional on a specified larger-domain realization CheungXVID. This paper does not discharge that condition.

A successor comparing VI with XVI-D must provide:

1. VI's actual coordinate equation and Cauchy data, including the derivative convention and admissible source space;

2. XVI-D's actual coordinate forcing and required Cauchy data;

3. a common domain on which both prescriptions are defined;

4. either equality of the two problems followed by uniqueness, or a detecting mismatch in forcing, initial data, or domain;

5. a separate analysis of any switched assignment whose first coefficient is used in the comparison.

A reported first-order switch obstruction is not automatically an obstruction to an independently defined coordinate Cauchy problem. Conversely, a second-order correction cannot retroactively change a fixed defective first coefficient.