diff --git a/doc/source/todo.rst b/doc/source/todo.rst
new file mode 100644
index 0000000..9a48d4b
--- /dev/null
+++ b/doc/source/todo.rst
@@ -0,0 +1,150 @@
+==================
+reclass to-do list
+==================
+
+Common set of classes
+---------------------
+A lot of the classes I have set up during the various stages of development of
+|reclass| are generic. It would probably be sensible to make them available as
+part of |reclass|, to give people a common baseline to work from, and to
+ensure a certain level of consistency between users.
+
+This could also provide a more realistic example to users on how to use
+|reclass|.
+
+Testing framework
+-----------------
+There is rudimentary testing in place, but it's inconsistent. I got
+side-tracked into discussions about the philosphy of mocking objects. This
+could all be fixed and unified.
+
+Also, storage, outputters, CLI and adapters have absolutely no tests yet…
+
+The testing framework should also incorporate the example classes mentioned
+above.
+
+Configurable file extension
+---------------------------
+Right now, ``.yml`` is hard-coded. This could be exported to the
+configuration file, or even given as a list, so that ``.yml`` and ``.yaml``
+can both be used.
+
+Actually, I don't think this is such a good idea. If we create too many
+options right now, it'll be harder to unify later. Please also see `issue #17
+<https://github.com/madduck/reclass/issues/17`_ for a discussion about this.
+
+Verbosity, debugging
+--------------------
+Verbose output and debug logging would be a very useful addition to help
+people understand what's going on, where data are being changed/merged, and to
+help solve problems.
+
+Data from CMS for interpolation
+-------------------------------
+Depending on the CMS in question, it would be nice if |reclass| had access to
+the host-specific data (facts, grains, etc.) and could use those in parameter
+interpolation. I can imagine this working for Salt, where the ``grains``
+dictionary (and results from previous external node classifiers) is made
+available to the external node classifiers, but I am not convinced this will
+be possible in Ansible and Puppet.
+
+On the other hand, providing CMS-specific data to reclass will make people
+depend on it, meaning Salt cannot be used with multiple tools anymore.
+
+The way to deal with that would be to map grains, facts, whatever the CMS
+calls them, to a shared naming scheme/taxonomy, but that's a painful task,
+I think. It would mean, however, that even templates could be shared between
+CMSs if they only use the data provided by reclass (i.e. grains/facts become
+pillar data).
+
+Membership information
+----------------------
+It would be nice if |reclass| could provide e.g. the Nagios master node with
+a list of clients that define it as their master. That would short-circuit
+Puppet's ``storeconfigs`` and Salt's ``mine``.
+
+The way I envision this currently is to provide something I call "inventory
+queries". For instance, the Nagios master node's reclass data would contain
+the following (``$[…]`` would denote interpolation to create a list, a bit
+like list comprehension)::
+
+  parameters:
+    nagios:
+      hosts: $[nagios:master == SELF.nodename]
+
+This would cause |reclass| to iterate the inventory and generate a list of all
+the nodes that define a parameter ``nagios:master`` whose value equals to the
+name of the current node.
+
+This could be greatly simplified. For instance, we could simply limit
+comparisons against the name of the current node and just specify
+
+::
+
+  $[nagios:master]
+
+which would be expanded to a list of node names whose pillar data includes
+``${nagios:master}`` that matches the current node's name.
+
+Or it could be made arbitrarily complex and flexible, e.g. any of the
+following::
+
+  $[nagios:master == SELF.nodename]                  # replace with nodename
+  $[nagios:master == SELF.nodename | nodename]       # name replacement value
+  $[nagios:master == SELF.nodename | nagios:nodeid]  # replace with pillar data
+  $[x:nagios:nodeid foreach x | x:nagios:master == SELF.nodename]
+  …
+
+I'd rather not code this up from scratch, so I am looking for ideas for reuse…
+
+Configuration file lookup improvements
+--------------------------------------
+Right now, the adapters and the CLI look for the :doc:`configuration file
+<configfile>` in a fixed set of locations. On of those derives from
+``OPT_INVENTORY_BASE_URI``, the default inventory base URI (``/etc/reclass``).
+This should probably be updated in case the user changes the URI.
+
+Furthermore, ``$CWD`` and ``~`` might not make a lot of sense in all
+use-cases.
+
+However, this might be better addressed by the following point:
+
+Adapter class hierarchy
+-----------------------
+At the moment, adapters are just imperative code. It might make more sense to
+wrap them in classes, which customise things like command-line and config file
+parsing.
+
+One nice way would be to generalise configuration file reading, integrate it
+with command-line parsing, and then allow the consumers (the adapters) to
+configure them, for instance, in the Salt adapter::
+
+  config_proxy = ConfigProxy()
+  config_proxy.set_configfile_search_path(['/etc/reclass', '/etc/salt'])
+  config_proxy.lock_config_option('output', 'yaml')
+
+The last call would effectively remove the ``--output`` config option from the
+CLI, and yield an error (or warning) if the option was encountered while
+parsing the configuration file.
+
+Furthermore, the class instances could become long-lived and keep a reference
+to a storage proxy, e.g. to prevent having to reload storage on every request.
+
+Node lists
+----------
+Class mappings are still experimental, and one of the reasons I am not too
+happy with them right now is that one would still need to provide node files
+for all nodes for ``inventory`` invocations. This is because class mappings
+can assign classes based on patterns or regular expressions, but it is not
+possible to turn a pattern or regular expression into a list of valid nodes.
+
+`Issue #9 <https://github.com/madduck/reclass/issues/9>`_ contains a lengthy
+discussion on this. At the moment, I am unsure what the best way forward is.
+
+Inventory filters
+-----------------
+As described in `issue #11 <https://github.com/madduck/reclass/issues/11>`_:
+provide a means to limit the enumeration of the inventory, according to node
+name patterns, or using classes white-/blacklists.
+
+.. include:: substs.inc