diff --git a/markbase-core/src/ssh_server/kex_exchange.rs b/markbase-core/src/ssh_server/kex_exchange.rs
index 2c15208..13da776 100644
--- a/markbase-core/src/ssh_server/kex_exchange.rs
+++ b/markbase-core/src/ssh_server/kex_exchange.rs
@@ -197,6 +197,7 @@ impl KexExchangeHandler {
         
         let mut hasher = Sha256::new();
         
+        // RFC 4253 Section 7: V_C and V_S are version strings (without \r\n based on testing)
         hasher.update(&(client_version.len() as u32).to_be_bytes());
         hasher.update(client_version.as_bytes());