diff --git a/src/core/ddsc/include/dds/dds.h b/src/core/ddsc/include/dds/dds.h
index 85d015f..089eea8 100644
--- a/src/core/ddsc/include/dds/dds.h
+++ b/src/core/ddsc/include/dds/dds.h
@@ -1324,7 +1324,7 @@ dds_create_writer(
  *
  * This operation registers an instance with a key value to the data writer and
  * returns an instance handle that could be used for successive write & dispose
- * operations. When the handle is not allocated, the function will return and
+ * operations. When the handle is not allocated, the function will return an
  * error and the handle will be un-touched.
  *
  * @param[in]  writer  The writer to which instance has be associated.
@@ -2035,7 +2035,7 @@ dds_waitset_attach(
  * @returns A dds_return_t indicating success or failure.
  *
  * @retval DDS_RETCODE_OK
- *             Entity attached.
+ *             Entity detached.
  * @retval DDS_RETCODE_ERROR
  *             An internal error has occurred.
  * @retval DDS_RETCODE_BAD_PARAMETER
@@ -2072,7 +2072,7 @@ dds_waitset_detach(
  * @returns A dds_return_t indicating success or failure.
  *
  * @retval DDS_RETCODE_OK
- *             Entity attached.
+ *             Trigger value set.
  * @retval DDS_RETCODE_ERROR
  *             An internal error has occurred.
  * @retval DDS_RETCODE_BAD_PARAMETER
diff --git a/src/core/ddsc/include/dds/ddsc/dds_public_qos.h b/src/core/ddsc/include/dds/ddsc/dds_public_qos.h
index 503a567..eb0a670 100644
--- a/src/core/ddsc/include/dds/ddsc/dds_public_qos.h
+++ b/src/core/ddsc/include/dds/ddsc/dds_public_qos.h
@@ -149,6 +149,8 @@ dds_qset_durability (dds_qos_t * __restrict qos, dds_durability_kind_t kind);
 
 /**
  * @brief Set the history policy of a qos structure.
+ * 
+ * Note that depth is only relevant for keep last. If you want limited history for keep all, use dds_qset_resource_limits().
  *
  * @param[in,out] qos - Pointer to a dds_qos_t structure that will store the policy
  * @param[in] kind - History kind value \ref DCPS_QoS_History
@@ -297,7 +299,7 @@ dds_qset_partition1 (
  *
  * @param[in,out] qos - Pointer to a dds_qos_t structure that will store the policy
  * @param[in] kind - Reliability kind
- * @param[in] max_blocking_time - Max blocking duration applied when kind is reliable.
+ * @param[in] max_blocking_time - Max blocking duration applied when kind is reliable. This is how long the writer will block when its history is full.
  */
 DDS_EXPORT void
 dds_qset_reliability (
diff --git a/src/ddsrt/include/dds/ddsrt/time.h b/src/ddsrt/include/dds/ddsrt/time.h
index 3570801..a604a5e 100644
--- a/src/ddsrt/include/dds/ddsrt/time.h
+++ b/src/ddsrt/include/dds/ddsrt/time.h
@@ -43,7 +43,7 @@ extern "C" {
 /** Absolute Time definition */
 typedef int64_t dds_time_t;
 
-/** Relative Time definition */
+/** Relative Time definition in nanoseconds */
 typedef int64_t dds_duration_t;
 
 /** @name Macro definition for time units in nanoseconds.