Open implementation
The exact implementation can be inspected, versioned and rerun.
Recreated
A reconstruction from documented sources, identified separately from the original executable.
Table-derived
Behaviour is transcribed from a published table, with the limits of that process recorded.
Black-box
Outputs are observable under a stated workflow; the internal implementation is closed.
Documented only
The procedure is documented but not represented by a runnable implementation.
Unavailable
A reproducible implementation is not available for the stated version or procedure.