diff --git a/Cantera/src/thermo/GibbsExcessVPSSTP.cpp b/Cantera/src/thermo/GibbsExcessVPSSTP.cpp
index 6958d2b6b..4019c3886 100644
--- a/Cantera/src/thermo/GibbsExcessVPSSTP.cpp
+++ b/Cantera/src/thermo/GibbsExcessVPSSTP.cpp
@@ -257,15 +257,7 @@ namespace Cantera {
     return 0;
   }
 
-    //@}
-    /// @name  Properties of the Standard State of the Species in the Solution
-    //@{
-
-     
-
-    //@}
-    /// @name Thermodynamic Values for the Species Reference States
-    //@{
+ 
 
   double GibbsExcessVPSSTP::checkMFSum(const doublereal * const x) const {
     doublereal norm = accumulate(x, x + m_kk, 0.0);
diff --git a/Cantera/src/thermo/GibbsExcessVPSSTP.h b/Cantera/src/thermo/GibbsExcessVPSSTP.h
index 75242aec8..c9d27094f 100644
--- a/Cantera/src/thermo/GibbsExcessVPSSTP.h
+++ b/Cantera/src/thermo/GibbsExcessVPSSTP.h
@@ -1,9 +1,9 @@
 /**
- *  @file gibbsExcessVPSSTP.h
+ *  @file GibbsExcessVPSSTP.h
  *   Header for intermediate ThermoPhase object for phases which
  *   employ gibbs excess free energy based formulations
  *  (see \ref thermoprops 
- * and class \link Cantera::gibbsExcessVPSSTP gibbsExcessVPSSTP\endlink).
+ * and class \link Cantera::GibbsExcessVPSSTP GibbsExcessVPSSTP\endlink).
  *
  * Header file for a derived class of ThermoPhase that handles
  * variable pressure standard state methods for calculating
@@ -517,6 +517,10 @@ namespace Cantera {
 
   protected:
 
+    //! utility routine to check mole fraction sum
+    /*!
+     * @param x   vector of mole fractions.
+     */
     double checkMFSum(const doublereal * const x) const;
 
   protected:
diff --git a/Cantera/src/thermo/MargulesVPSSTP.h b/Cantera/src/thermo/MargulesVPSSTP.h
index 5f78c12fb..128caa440 100644
--- a/Cantera/src/thermo/MargulesVPSSTP.h
+++ b/Cantera/src/thermo/MargulesVPSSTP.h
@@ -1,5 +1,5 @@
 /**
- *  @file  Margules.h
+ *  @file  MargulesVPSSTP.h
  *   Header for intermediate ThermoPhase object for phases which
  *   employ gibbs excess free energy based formulations
  *  (see \ref thermoprops 
diff --git a/Cantera/src/thermo/PDSS.h b/Cantera/src/thermo/PDSS.h
index 1f542c417..ad989cfe8 100644
--- a/Cantera/src/thermo/PDSS.h
+++ b/Cantera/src/thermo/PDSS.h
@@ -100,6 +100,21 @@ namespace Cantera {
    *        pressure dependencies to these thermo functions.
    *      .
    *
+   *   - PDSS_SSVol
+   *      - standardState model = "constant_incompressible" || model == "constant"
+   *      - standardState model = "temperature_polynomial"
+   *      - standardState model = "density_temperature_polynomial"
+   *      - This model assumes that the species in the phase obey a
+   *        fairly general equation of state, but one that separates out
+   *        the calculation of the standard state density and/or volume.
+   *        Models include a cubic polynomial in temperature for either
+   *        the standard state volume or the standard state density.
+   *        The manager uses a SimpleThermo object to handle the
+   *        calculation of the reference state. This object then adds the
+   *        pressure dependencies and the volume terms to these thermo functions
+   *        to complete the representation.
+   *      .
+   *
    *   - PDSS_Water_
    *      - standardState model = "Water"
    *      - This model assumes that