Make import algorithm explicit.

Mention extension naming discussion.

pep-0382.txt

@@ -115,9 +115,20 @@ packages are added to the set sys.namespace_packages.
 extend_path will be extended to recognize namespace packages according
 to this PEP, and avoid adding directories twice to __path__.
 
-No other change to the importing mechanism is made; searching
+No other change to the importing mechanism is made; searching modules
-modules (including __init__.py) will continue to stop at the first
+(including __init__.py) will continue to stop at the first module
-module encountered.
+encountered. In summary, the process import a package foo works like
+this:
+
+ 1. sys.path is search for a directory foo, or a file foo.<ext>.
+    If a file is found, it is treated as a module, and imported.
+ 2. if it is a directory, it checks for *.pkg files. If it finds
+    any, a package is created, and its __path__ is extended.
+ 3. The __init__ module is imported; this import will search the
+    __path__ that got computed already.
+ 4. If neither a *.pkg file nor an __init__.py was found, the
+    directory is skipped, and search for the module/package
+    continues.
 
 Discussion
 ==========
@@ -149,6 +160,9 @@ having users and tools starting to special-case 2.7). Prospective
 users of this feature are encouraged to comment on this particular
 question.
 
+It also has been proposed to rename the extension from .pkg to
+something else.
+
 Copyright
 =========