Multiple Data Sections
Formalizes the multiple-data section proposal first circulated last year.
- Current single data section P21 files are still completely legal.
- When multiple sections used, data in each is defined by a single schema (although a list is used as with file_schema.) Each section can have a name. If used, the names must be unique.
- References between sections legal. Type compatibility of references an EXPRESS issue, not Part 21.
- Header file_schema contains the complete list of schemas used by the file.