core/lib/Drupal/Core/Entity/RevisionableInterface.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/core/lib/Drupal/Core/Entity/RevisionableInterface.php b/core/lib/Drupal/Core/Entity/RevisionableInterface.php
index 14690e3..787d7ed 100644
--- a/core/lib/Drupal/Core/Entity/RevisionableInterface.php
+++ b/core/lib/Drupal/Core/Entity/RevisionableInterface.php
@@ -4,6 +4,14 @@
 
 /**
  * Provides methods for an entity to support revisions.
+ *
+ * Note: one MUST NOT use this interface in conditional logic, because it does
+ * not indicate whether an entity type is revisionable. All content entity types
+ * implement this interface, but not all of them are revisionable. To detect
+ * whether an entity type is revisionable in conditional logic, use
+ * EntityTypeInterface::isRevisionable().
+ *
+ * @see \Drupal\Core\Entity\EntityTypeInterface::isRevisionable()
  */
 interface RevisionableInterface {