2.2.5 Property Storage
Files in Word Binary File Format store the properties of characters, paragraphs, tables, pictures, and sections as lists of differences from the default. A Prl specifies each difference. It consists of a Single Property Modifier (Sprm) and its operand. An application can determine the final set of properties by applying lists of Prls in the order that is specified in section 2.4.6 (Applying Properties).
An application SHOULD<7> skip any Prl that corresponds to a property or feature not present in the application by using Sprm.spra to determine the size of the Prl to skip.
The definition of each Sprm in section 2.6 (Single Property Modifiers) specifies the default value for the corresponding property.
If multiple Prls modify the same property, the last one that is applied determines the final value of that property unless otherwise specified in a Sprm definition in section 2.6.
Any restrictions on the ordering of Prls are included in the specifications of the individual Sprms involved in the restriction. See sprmTDelete as an example.
In cases where multiple Sprms modify the same property, but are supported by different application versions, an application generating a file MUST first emit the Sprm that has the lower ispmd, followed by the Sprm that has the higher ispmd. For example, sprmPBrcTop80 and sprmPBrcTop both modify the top border of a paragraph, but sprmPBrcTop can express more colors. If an application emits only sprmPBrcTop, applications that support only sprmPBrcTop80 do not display a top border.