Status: IN
The primary sends PRE-PREPARE but not PREPARE; `_handle_prepare` rejects PREPAREs from the primary, and the primary's code path in `_handle_pre_prepare` skips sending a PREPARE — this asymmetry is why the prepared threshold is 2f not 2f+1.
Source: entries/2026/05/29/byzantine-fault-tolerance-pbft-_check_prepared.md