diff --git a/include/cantera/kinetics/RateCoeffMgr.h b/include/cantera/kinetics/RateCoeffMgr.h
index 8368ccec4..ca5fad8df 100644
--- a/include/cantera/kinetics/RateCoeffMgr.h
+++ b/include/cantera/kinetics/RateCoeffMgr.h
@@ -116,7 +116,7 @@ public:
 protected:
     std::vector<R>             m_rates;
     std::vector<size_t>           m_rxn;
-    vector_fp              m_const; // not used
+    vector_fp              m_const; //!< @deprecated not used
 };
 
 
diff --git a/src/equil/vcs_VolPhase.h b/src/equil/vcs_VolPhase.h
index f52ca3d4a..01199e7f5 100644
--- a/src/equil/vcs_VolPhase.h
+++ b/src/equil/vcs_VolPhase.h
@@ -685,6 +685,7 @@ public:
      * This ventures into the idea of installing a physical location
      * into a thermodynamics program. This unknown is currently not
      * being used.
+     * @deprecated
      */
     int Domain_ID;