In preparing, formulating and filing for Federal Disability Retirement benefits from the U.S. Office of Personnel Management, whether under FERS or CSRS, it is important not to confuse the difference between that which is central in proving one’s Federal Disability Retirement application, from that which is merely of persuasive import.  In some cases, there may be a necessity, for very pragmatic reasons, to deliberately switch the two; but as a general rule, the argument for persuasive documentation should be used as secondary sources of proof. […]