-- Run in a clean directory.
$ tarantool -i
Tarantool 3.4.0-entrypoint-151-g08690f65b
type 'help' for interactive help
tarantool> box.cfg{}
tarantool> box.schema.downgrade('2.11.5')
tarantool> box.space._schema:get({'version'})
---
- ['version', 2, 11, 1]
...

This may affect how persistent names are handled by 3.x code after downgrading to the 2.11.5 schema version.

The 2.11.5 release instroduces (46cac24) this dummy schema version to mark its readiness to accept persistent names¹. The 3.x code knows that 2.11.5+ releases are ready for the persistent names and the names are written only on this and newer schema versions (0af0882).