There are three means to undertand the regulation correctly. The Federal Register preamble, followed by the FAA Chief Legal Counsel letters of interpretation, followed by the regulation itself. A fourth non-precedent setting means of understanding how the regulation has been applied in specific cases, which does not interpret regulation, are Administrative Law Judge (ALJ) decisions in reference to enforcement action.
These sources, in order, help understand the regulation.
Company operations specifications, followed by the regulation, followed by company polices, help understand the application of the regulation in context, as it is to be applied to a specific operator.