diff --git a/libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h b/libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h
index 5772ede1..14853bc0 100644
--- a/libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h
+++ b/libwvdrmengine/oemcrypto/include/OEMCryptoCENC.h
@@ -143,6 +143,11 @@
  * This can be used to implement content key rotation without requiring new
  * licenses, or access to multiple pieces of content with a single license.
  *
+ * For OEMCrypto supporting CE CDM and Android MediaDrm, each license session
+ * must support at least one entitled key session. For OEMcrypto supporting
+ * MediaCas, each license session must support at least six entitled key
+ * sessions.
+ *
  * @defgroup test_verify Test and Verification API
  * Functions that are designed to help test OEMCrypto and the device. They are
  * not used during normal operation. Some functions, like those that test the
@@ -1700,6 +1705,9 @@ OEMCryptoResult OEMCrypto_QueryKeyControl(OEMCrypto_SESSION session,
  * license. For CAS support, we also require that OEMCrypto support at least
  * six entitled key sessions per license.
  *
+ * If a call to this function would create too many entitled key sessions for
+ * oec_session, then the function returns OEMCrypto_ERROR_TOO_MANY_SESSIONS.
+ *
  * @param[in] oec_session: handle for the OEMCrypto session to be associated
  *    with the created entitled key session.
  * @param[out] key_session: id of the created entitled key session.