diff --git a/mdbx.h b/mdbx.h
index 8f86694b..8bf0eac5 100644
--- a/mdbx.h
+++ b/mdbx.h
@@ -972,13 +972,25 @@ enum MDBX_env_flags_t {
    * be written to disk, while the itself B-tree not yet. In that case, the
    * database will be corrupted!
    *
-   * \see MDBX_NOMETASYNC \see MDBX_SAFE_NOSYNC \see MDBX_UTTERLY_NOSYNC
+   * \see MDBX_SYNC_DURABLE \see MDBX_NOMETASYNC \see MDBX_SAFE_NOSYNC
+   * \see MDBX_UTTERLY_NOSYNC
    *
    * @{ */
 
+  /** Default robust and durable sync mode.
+   *
+   * Metadata is written and flushed to disk after a data is written and
+   * flushed, which guarantees the integrity of the database in the event
+   * of a crash at any time.
+   *
+   * \attention Please do not use other modes until you have studied all the
+   * details and are sure. Otherwise, you may lose your users' data, as happens
+   * in [Miranda NG](https://www.miranda-ng.org/) messenger. */
+  MDBX_SYNC_DURABLE = 0,
+
   /** Don't sync the meta-page after commit.
    *
-   * Flush system buffers to disk only once per transaction, omit the
+   * Flush system buffers to disk only once per transaction commit, omit the
    * metadata flush. Defer that until the system flushes files to disk,
    * or next non-\ref MDBX_RDONLY commit or \ref mdbx_env_sync(). Depending on
    * the platform and hardware, with \ref MDBX_NOMETASYNC you may get a doubling