diff --git a/src/script/standard.h b/src/script/standard.h
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -41,11 +41,18 @@
 extern bool fAcceptDatacarrier;
 
 /**
- * Mandatory script verification flags that all new blocks must comply with for
- * them to be valid (but old blocks may not comply with).
- *
- * Failing one of these tests may trigger a DoS ban - see CheckInputs() for
- * details.
+ * A set of flags used for a variety of unrelated purposes:
+ * - Together with STANDARD_SCRIPT_VERIFY_FLAGS, this is used to calculate
+ *   STANDARD_NOT_MANDATORY_VERIFY_FLAGS, which is the set of flags that
+ *   transactions are allowed to violate that result in only rejecting the
+ *   transaction, instead of banning the peer.
+ *   (see CheckInputs() in validation.cpp).
+ * - Used in some tests as an arbitrary set of flags, for some strange reason.
+ * - Used in the (deprecated) DataFromTransaction scriptSig analyzer during
+ *   signing, for some strange reason.
+ * - Note this is *not* used in block validation. It also does not represent the
+ *   validation flags for a typical current block. Many blocks, both past and
+ *   current, contain transactions that outright fail under this flag set.
  */
 static const uint32_t MANDATORY_SCRIPT_VERIFY_FLAGS =
     SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC |