diff --git a/src/gui/gtk-lumiera.hpp b/src/gui/gtk-lumiera.hpp
index fec25c9b3..c1b5a773a 100644
--- a/src/gui/gtk-lumiera.hpp
+++ b/src/gui/gtk-lumiera.hpp
@@ -62,7 +62,7 @@ extern "C" {
 #endif
 
 /**
- * The namespace of all GUI code.
+ * Lumiera GTK GUI implementation root.
  */
 namespace gui {
   
diff --git a/src/proc/common.hpp b/src/proc/common.hpp
index e1352a308..2d5c929d3 100644
--- a/src/proc/common.hpp
+++ b/src/proc/common.hpp
@@ -46,7 +46,7 @@
 #include "lib/util.hpp"
 #include "lib/lumitime.hpp"
 #include "lib/symbol.hpp"
-#include "lib/error.hpp"   ///< pulls in NoBug via loggging.h
+#include "lib/error.hpp"   // pulls in NoBug via loggging.h
 
 
 /**
diff --git a/src/proc/facade.hpp b/src/proc/facade.hpp
index 5f4531617..b231359f3 100644
--- a/src/proc/facade.hpp
+++ b/src/proc/facade.hpp
@@ -29,6 +29,12 @@
 
 
 
+/**
+ * Lumiera Proc-Layer implementation root.
+ * The middle layer of the application holds a session with the
+ * high-level model, to be translated by the Builder into a node network,
+ * which can be \em performed by the Engine to render output.
+ */
 namespace proc {