diff --git a/src/libxrpl/ledger/helpers/PermissionedDEXHelpers.cpp b/src/libxrpl/ledger/helpers/PermissionedDEXHelpers.cpp
index d65462f0cd..456c4e95d6 100644
--- a/src/libxrpl/ledger/helpers/PermissionedDEXHelpers.cpp
+++ b/src/libxrpl/ledger/helpers/PermissionedDEXHelpers.cpp
@@ -62,7 +62,8 @@ offerInDomain(
 
     if (view.rules().enabled(fixSecurity3_1_3))
     {
-        // post-fixSecurity3_1_3: also catches empty sfAdditionalBooks (size == 0)
+        // post-fixSecurity3_1_3: a valid hybrid offer must have
+        // sfAdditionalBooks present with exactly 1 entry
         if (sleOffer->isFlag(lsfHybrid) &&
             (!sleOffer->isFieldPresent(sfAdditionalBooks) ||
              sleOffer->getFieldArray(sfAdditionalBooks).size() != 1))
@@ -74,7 +75,8 @@ offerInDomain(
     }
     else
     {
-        // pre-fixSecurity3_1_3: only check for missing sfAdditionalBooks
+        // pre-fixSecurity3_1_3: a valid hybrid offer must have
+        // sfAdditionalBooks present (size is not checked)
         if (sleOffer->isFlag(lsfHybrid) && !sleOffer->isFieldPresent(sfAdditionalBooks))
         {
             JLOG(j.error()) << "Hybrid offer " << offerID << " missing AdditionalBooks field";