ISSP package

Every upgrade publishes a new package with its own ID. All versions share the original ID (version 1's) 0xd0ea…4ae8, and the version number counts up, so the highest number is the current code, version 31 here.

A transaction names the exact package ID it calls, so older versions can still be called unless the package itself refuses them, often with a version check on a shared object.

A type keeps the ID of the version that first defined it. Types from version 1 use the original ID for good, while a type added in a later upgrade uses that version's ID.