diff --git a/src/proc/asset.hpp b/src/proc/asset.hpp
index 04e01a73c..def4a02ee 100644
--- a/src/proc/asset.hpp
+++ b/src/proc/asset.hpp
@@ -86,6 +86,7 @@ namespace asset {
   
   //NOBUG_DECLARE_FLAG (assetmem);
   
+  typedef size_t HashVal;                        /////////////////TICKET #722
   
   /** 
    * thin wrapper around a size_t hash ID 
@@ -103,10 +104,10 @@ namespace asset {
   class ID
     {
     public:
-      const size_t hash;
-      ID (size_t id)         : hash(id)         {}
+      const HashVal hash;
+      ID (HashVal id)        : hash(id)         {}
       ID (const KIND& asset) : hash(asset.getID()) {}
-      operator size_t()  const { return hash; }
+      operator HashVal() const { return hash; }
     };
     
   class DB;
diff --git a/src/proc/asset/codec.cpp b/src/proc/asset/codec.cpp
index 8604a89d6..e98608375 100644
--- a/src/proc/asset/codec.cpp
+++ b/src/proc/asset/codec.cpp
@@ -23,8 +23,7 @@
 
 #include "proc/asset/codec.hpp"
 
-namespace asset
-  {
+namespace asset {
 
 
 
diff --git a/src/proc/asset/codec.hpp b/src/proc/asset/codec.hpp
index 40ee70370..e46fcf5dd 100644
--- a/src/proc/asset/codec.hpp
+++ b/src/proc/asset/codec.hpp
@@ -28,8 +28,7 @@
 
 
 
-namespace asset
-  {
+namespace asset {
   
   /**
    * description of some media data decoder or encoder facility
@@ -38,8 +37,8 @@ namespace asset
     {
       
     };
-    
-    
-    
+  
+  
+  
 } // namespace asset
 #endif
diff --git a/src/proc/asset/compoundmedia.hpp b/src/proc/asset/compoundmedia.hpp
index 534993391..987632408 100644
--- a/src/proc/asset/compoundmedia.hpp
+++ b/src/proc/asset/compoundmedia.hpp
@@ -32,8 +32,7 @@ using std::vector;
 
 
 
-namespace asset
-  {
+namespace asset {
 
 
   /**
diff --git a/src/proc/asset/media.hpp b/src/proc/asset/media.hpp
index fc3bf8cd1..ba6b10558 100644
--- a/src/proc/asset/media.hpp
+++ b/src/proc/asset/media.hpp
@@ -59,7 +59,7 @@ namespace asset {
   class ID<Media> : public ID<Asset>
     {
     public:
-      ID (size_t id);
+      ID (HashVal id);
       ID (const Media&);
     };
 
@@ -130,7 +130,7 @@ namespace asset {
     // definition of ID<Media> ctors is possible now,
    //  after providing full definition of class Media
 
-  inline ID<Media>::ID(size_t id)          : ID<Asset> (id)            {};
+  inline ID<Media>::ID(HashVal id)         : ID<Asset> (id)            {};
   inline ID<Media>::ID(const Media& media) : ID<Asset> (media.getID()) {};
   
   
diff --git a/src/proc/asset/meta.hpp b/src/proc/asset/meta.hpp
index d3f543ab4..5a5ac592f 100644
--- a/src/proc/asset/meta.hpp
+++ b/src/proc/asset/meta.hpp
@@ -55,7 +55,7 @@ namespace asset {
   class ID<Meta> : public ID<Asset>
     {
     public:
-      ID (size_t id);
+      ID (HashVal id);
       ID (const Meta&);
     };
   
@@ -84,7 +84,7 @@ namespace asset {
     // definition of ID<Meta> ctors is possible now,
    //  after providing full definition of class Proc
   
-  inline ID<Meta>::ID(size_t id)        : ID<Asset> (id)           {};
+  inline ID<Meta>::ID(HashVal id)       : ID<Asset> (id)           {};
   inline ID<Meta>::ID(const Meta& meta) : ID<Asset> (meta.getID()) {};
   
   typedef P<Meta> PMeta;
diff --git a/src/proc/asset/pipe.hpp b/src/proc/asset/pipe.hpp
index 64e3e991c..922dec444 100644
--- a/src/proc/asset/pipe.hpp
+++ b/src/proc/asset/pipe.hpp
@@ -44,7 +44,7 @@ namespace asset {
   class ID<Pipe> : public ID<Struct>
     {
     public:
-      ID (size_t id);
+      ID (HashVal id);
       ID (const Pipe&);
     };
   
@@ -95,7 +95,7 @@ namespace asset {
     
    // catch up with postponed definition of ID<Struct> ctors...
   //
-  inline ID<Pipe>::ID(size_t id)        : ID<Struct> (id)           {};
+  inline ID<Pipe>::ID(HashVal id)       : ID<Struct> (id)           {};
   inline ID<Pipe>::ID(Pipe const& pipe) : ID<Struct> (pipe.getID()) {};
   
   
diff --git a/src/proc/asset/preview.cpp b/src/proc/asset/preview.cpp
index 82247149e..f6aa426d6 100644
--- a/src/proc/asset/preview.cpp
+++ b/src/proc/asset/preview.cpp
@@ -23,29 +23,27 @@
 
 #include "proc/asset/preview.hpp"
 
-namespace asset
-  {
+namespace asset {
   
   
-  namespace
+  namespace {
+    /** @internal derive a sensible asset ident tuple when creating 
+     *  a proxy placeholder media based on some existing asset::Media
+     *  @todo getting this one right is important for the handling
+     *        of "proxy editing"....
+     */
+    const Asset::Ident
+    createProxyIdent (const Asset::Ident& mediaref)
     {
-      /** @internal derive a sensible asset ident tuple when creating 
-       *  a proxy placeholder media based on some existing asset::Media
-       *  @todo getting this one right is important for the handling
-       *        of "proxy editing"....
-       */
-      const Asset::Ident
-      createProxyIdent (const Asset::Ident& mediaref)
-        {
-          string name (mediaref.name + "-proxy");  // TODO something sensible here; append number, sanitise etc.
-          Category category (mediaref.category);
-          TODO ("put it in another subfolder within the same category??");
-          return Asset::Ident (name, category, 
-                               mediaref.org, 
-                               mediaref.version );
-          
-        }
+      string name (mediaref.name + "-proxy");  // TODO something sensible here; append number, sanitise etc.
+      Category category (mediaref.category);
+      TODO ("put it in another subfolder within the same category??");
+      return Asset::Ident (name, category, 
+                           mediaref.org, 
+                           mediaref.version );
+      
     }
+  }//(End)implementation helper
   
   
   
@@ -62,8 +60,8 @@ namespace asset
     this->defineDependency (mediaref);
     UNIMPLEMENTED ("do something to setup proxy media");
   }
-
-
-
-
+  
+  
+  
+  
 } // namespace asset
diff --git a/src/proc/asset/preview.hpp b/src/proc/asset/preview.hpp
index e36e22ea4..8aec81b5f 100644
--- a/src/proc/asset/preview.hpp
+++ b/src/proc/asset/preview.hpp
@@ -28,9 +28,8 @@
 
 
 
-namespace asset
-  {
-
+namespace asset {
+  
   /**
    * special placeholder denoting an alternative version of the media data,
    * typically with lower resolution ("proxy media")
@@ -41,8 +40,8 @@ namespace asset
       Preview (Media& mediaref);
       friend class MediaFactory;
     };
-    
-    
-    
+  
+  
+  
 } // namespace asset
 #endif
diff --git a/src/proc/asset/proc.cpp b/src/proc/asset/proc.cpp
index 764c3a928..fe53bd336 100644
--- a/src/proc/asset/proc.cpp
+++ b/src/proc/asset/proc.cpp
@@ -27,15 +27,8 @@
 #include "include/logging.h"
 
 
-namespace asset
-  {
+namespace asset {
   
-  namespace // Implementation details
-  {
-    /** helper: .....*/
-  } 
-
-
   
   ProcFactory Proc::create;  ///< storage for the static ProcFactory instance
   
diff --git a/src/proc/asset/proc.hpp b/src/proc/asset/proc.hpp
index b99a3f364..35618627b 100644
--- a/src/proc/asset/proc.hpp
+++ b/src/proc/asset/proc.hpp
@@ -26,7 +26,7 @@
  ** For the different <i>Kinds</i> of Assets, we use sub-interfaces inheriting
  ** from the general Asset interface. To be able to get asset::Proc instances
  ** directly from the AssetManager, we define a specialisation of the Asset ID.
- **
+ ** 
  ** @see asset.hpp for explanation
  ** @see ProcFactory creating concrete asset::Proc instances
  **
@@ -57,12 +57,12 @@ namespace asset {
   class ID<Proc> : public ID<Asset>
     {
     public:
-      ID (size_t id);
+      ID (HashVal id);
       ID (const Proc&);
     };
-
-    
-    
+  
+  
+  
   /**
    * key abstraction: data processing asset
    * @todo just a stub, have to figure out what a asset::Proc is
@@ -94,18 +94,18 @@ namespace asset {
       virtual ProcFunc*
       resolveProcessor()  const =0;
       
-
+      
       
     protected:
       Proc (const Asset::Ident& idi) : Asset(idi) {}  //////////////TODO
       friend class ProcFactory;
     };
-    
-    
+  
+  
     // definition of ID<Proc> ctors is possible now,
    //  after providing full definition of class Proc
-
-  inline ID<Proc>::ID(size_t id)        : ID<Asset> (id)           {};
+  
+  inline ID<Proc>::ID(HashVal id)       : ID<Asset> (id)           {};
   inline ID<Proc>::ID(const Proc& proc) : ID<Asset> (proc.getID()) {};
   
   
@@ -120,11 +120,11 @@ namespace asset {
       typedef P<asset::Proc> PType;
        
       PType operator() (Asset::Ident& key);      ////////////TODO define actual operation 
-
+      
     };
-
-    
-    
-    
+  
+  
+  
+  
 } // namespace asset
 #endif
diff --git a/src/proc/asset/procpatt.hpp b/src/proc/asset/procpatt.hpp
index 93362055f..bd9b025df 100644
--- a/src/proc/asset/procpatt.hpp
+++ b/src/proc/asset/procpatt.hpp
@@ -37,15 +37,15 @@ namespace asset {
   
   using lumiera::P;
   using lib::Symbol;
-
+  
   class Proc;
   class ProcPatt;
   class BuildInstruct; 
   typedef P<const asset::Proc> PProc;
   typedef P<const asset::ProcPatt> PProcPatt;
   
-  typedef vector<BuildInstruct> InstructionSequence;    
-
+  typedef vector<BuildInstruct> InstructionSequence;
+  
   /**
    * "Processing Pattern" is a structural Asset 
    * representing information how to build some part 
@@ -56,7 +56,7 @@ namespace asset {
     {
       InstructionSequence instructions_;
       
-      ProcPatt (const Asset::Ident&, const InstructionSequence&);      
+      ProcPatt (const Asset::Ident&, const InstructionSequence&);
       
     protected:
       explicit ProcPatt (const Asset::Ident& idi);
@@ -67,11 +67,11 @@ namespace asset {
       
       ProcPatt& attach (Symbol where, PProc& node);
       ProcPatt& operator+= (PProcPatt& toReuse);
-
+      
     };
-    
-    
-    
-    
+  
+  
+  
+  
 } // namespace asset
 #endif
diff --git a/src/proc/asset/sequence.hpp b/src/proc/asset/sequence.hpp
index 0a4ac35fc..c1ce02704 100644
--- a/src/proc/asset/sequence.hpp
+++ b/src/proc/asset/sequence.hpp
@@ -86,7 +86,7 @@ namespace asset {
     , public lib::AutoRegistered<Sequence>
     {
       typedef mobject::session::RTrack RTrack;
-
+      
       Sequence (Ident const&);                //////////////////////////////////////////////TICKET #692  pass in track here
       
     public:
@@ -100,7 +100,7 @@ namespace asset {
     
   
   typedef P<Sequence> PSequence;
-    
+  
 ///////////////////////////TODO currently just fleshing the API
   
   
diff --git a/src/proc/asset/struct.hpp b/src/proc/asset/struct.hpp
index c5331ac20..9a9e84caa 100644
--- a/src/proc/asset/struct.hpp
+++ b/src/proc/asset/struct.hpp
@@ -87,12 +87,12 @@ namespace asset {
   class ID<Struct> : public ID<Asset>
     {
     public:
-      ID (size_t id);
+      ID (HashVal id);
       ID (const Struct&);
     };
-    
-    
-    
+  
+  
+  
   /**
    * key abstraction: structural asset
    * Created automatically as a sideeffect of building the structure
@@ -125,7 +125,7 @@ namespace asset {
     // definition of ID<Struct> ctors is possible now,
    //  after providing full definition of class Struct
   
-  inline ID<Struct>::ID(size_t id)          : ID<Asset> (id)           {};
+  inline ID<Struct>::ID(HashVal id)         : ID<Asset> (id)           {};
   inline ID<Struct>::ID(const Struct& stru) : ID<Asset> (stru.getID()) {};
   
   
diff --git a/src/proc/asset/unknown.cpp b/src/proc/asset/unknown.cpp
index e1b50cae7..3fa2e4ae9 100644
--- a/src/proc/asset/unknown.cpp
+++ b/src/proc/asset/unknown.cpp
@@ -27,8 +27,9 @@
 
 using boost::format;
 
-namespace asset
-  {
+namespace asset {
+  
+  LUMIERA_ERROR_DEFINE (ORIG_NOT_FOUND, "Media referred by placeholder not found");
   
   
   
@@ -60,8 +61,6 @@ namespace asset
                                     );
   }
   
-  LUMIERA_ERROR_DEFINE (ORIG_NOT_FOUND, "Media referred by placeholder not found");
-
   
   
 } // namespace asset
diff --git a/src/proc/asset/unknown.hpp b/src/proc/asset/unknown.hpp
index 48b1faa09..0402f6bc7 100644
--- a/src/proc/asset/unknown.hpp
+++ b/src/proc/asset/unknown.hpp
@@ -28,12 +28,11 @@
 
 
 
-namespace asset
-  {
+namespace asset {
+  
   
-
   const lumiera::Time DUMMY_TIME (25); ///< @todo solve config management
-
+  
   /**
    * Placeholder Asset for unknown or unavailable media source.
    * @todo maybe do special handling of the media length, allowing
@@ -50,11 +49,11 @@ namespace asset
       virtual Media::PMedia getOrg()  throw(lumiera::error::Invalid);
       
     };
-    
+  
   LUMIERA_ERROR_DECLARE (ORIG_NOT_FOUND);
-    
-    
-    
-    
+  
+  
+  
+  
 } // namespace asset
 #endif