diff --git a/src/driver.h b/src/driver.h
index 7dc047a..978e144 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -44,7 +44,8 @@ typedef struct store_conf {
 } store_conf_t;
 
 /* For message->flags */
-/* Keep the mailbox driver flag definitions in sync! */
+/* Keep the mailbox driver flag definitions in sync: */
+/* grep for MAILBOX_DRIVER_FLAG */
 /* The order is according to alphabetical maildir flag sort */
 #define F_DRAFT	     (1<<0) /* Draft */
 #define F_FLAGGED    (1<<1) /* Flagged */
diff --git a/src/drv_imap.c b/src/drv_imap.c
index 05afa09..fd46a0b 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -243,6 +243,9 @@ static int imap_deref( imap_store_t *ctx );
 
 static void imap_invoke_bad_callback( imap_store_t *ctx );
 
+/* Keep the mailbox driver flag definitions in sync: */
+/* grep for MAILBOX_DRIVER_FLAG */
+/* The order is according to alphabetical maildir flag sort */
 static const char *Flags[] = {
 	"Draft",
 	"Flagged",
diff --git a/src/drv_maildir.c b/src/drv_maildir.c
index 4a94696..31436f9 100644
--- a/src/drv_maildir.c
+++ b/src/drv_maildir.c
@@ -108,6 +108,9 @@ debug( const char *msg, ... )
 	va_end( va );
 }
 
+/* Keep the mailbox driver flag definitions in sync: */
+/* grep for MAILBOX_DRIVER_FLAG */
+/* The order is according to alphabetical maildir flag sort */
 static const char Flags[] = { 'D', 'F', 'R', 'S', 'T' };
 
 static uchar
diff --git a/src/drv_proxy.c b/src/drv_proxy.c
index 5010f60..43d7411 100644
--- a/src/drv_proxy.c
+++ b/src/drv_proxy.c
@@ -55,6 +55,9 @@ debugn( const char *msg, ... )
 	va_end( va );
 }
 
+/* Keep the mailbox driver flag definitions in sync: */
+/* grep for MAILBOX_DRIVER_FLAG */
+/* The order is according to alphabetical maildir flag sort */
 static const char Flags[] = { 'D', 'F', 'R', 'S', 'T' };
 
 static char *
diff --git a/src/sync.c b/src/sync.c
index 7397db2..d88344d 100644
--- a/src/sync.c
+++ b/src/sync.c
@@ -97,6 +97,9 @@ Fprintf( FILE *f, const char *msg, ... )
 }
 
 
+/* Keep the mailbox driver flag definitions in sync: */
+/* grep for MAILBOX_DRIVER_FLAG */
+/* The order is according to alphabetical maildir flag sort */
 static const char Flags[] = { 'D', 'F', 'R', 'S', 'T' };
 
 static int