Certain text classes can be further subdivided into parts. Like common areas, named parts can be shared between sections and are defined with the longest length and most restrictive alignment of all contributing sections. Unlike common areas, they must be defined in classes other than B_TEXT. Initializing data in parts is supported for PO3 and later format program objects.
Parts and common areas cannot share the same storage. While both sharing methods can coexist in the same program module, a single shared data area must use one or the other. Older compilers will continue to use common areas for data sharing, whereas newer compilers will utilize parts.