diff --git a/stand/common/bootstrap.h b/stand/common/bootstrap.h
index 0c6462f8d1a..88ee6de2e52 100644
--- a/stand/common/bootstrap.h
+++ b/stand/common/bootstrap.h
@@ -326,7 +326,8 @@ SET_DECLARE(Xcommand_set, struct bootblk_command);
  * The intention of the architecture switch is to provide a convenient
  * encapsulation of the interface between the bootstrap MI and MD code.
  * MD code may selectively populate the switch at runtime based on the
- * actual configuration of the target system.
+ * actual configuration of the target system, though some routines are
+ * mandatory.
  */
 struct arch_switch
 {