diff --git a/ptvp35/__init__.py b/ptvp35/__init__.py
index c9565ec..71dcfde 100644
--- a/ptvp35/__init__.py
+++ b/ptvp35/__init__.py
@@ -54,7 +54,9 @@ class LineRequest(Request):
 
 
 class KVFactory:
-    """note: unstable signature."""
+    """this class is for working with already normalised data values, not for data transformation (e.g. reducing keys to a common form).
+that functionality may be added in the future, though, probably, only for custom DbConnection implementations.
+note: unstable signature."""
 
     __slots__ = ()
 
@@ -216,7 +218,7 @@ class DbConnection:
 
     def __init__(
             self,
-            parametres: 'DbParametres',
+            parametres: DbParametres,
             /
     ) -> None:
         self.__kvfactory = parametres.kvfactory
@@ -511,10 +513,10 @@ intended for heavy tasks."""
         await self._initialize_running()
 
     @classmethod
-    async def create(cls, parametres: 'DbParametres', /) -> 'DbConnection':
+    async def create(cls, parametres: DbParametres, /) -> 'DbConnection':
         """connect to the factory.
 note: unstable signature."""
-        dbconnection = DbConnection(parametres)
+        dbconnection = cls(parametres)
         await dbconnection._initialize()
         return dbconnection