# -*- coding: utf-8 -*-
#
# django-filter documentation build configuration file, created by
# sphinx-quickstart on Mon Sep 17 11:25:20 2012.
#
# This file is execfile()d with the current directory set to its containing dir.
#
# Note that not all possible configuration values are present in this
# autogenerated file.
#
# All configuration values have a default; values that are commented out
# serve to show the default.

import sys, os

# If extensions (or modules to document with autodoc) are in another directory,
# add these directories to sys.path here. If the directory is relative to the
# documentation root, use os.path.abspath to make it absolute, like shown here.
#sys.path.insert(0, os.path.abspath('.'))

# -- General configuration -----------------------------------------------------

# If your documentation needs a minimal Sphinx version, state it here.
#needs_sphinx = '1.0'

# Add any Sphinx extension module names here, as strings. They can be extensions
# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
extensions = []

# Add any paths that contain templates here, relative to this directory.
templates_path = ['_templates']

# The suffix of source filenames.
source_suffix = '.txt'

# The encoding of source files.
#source_encoding = 'utf-8-sig'

# The master toctree document.
master_doc = 'index'

# General information about the project.
project = u'django-filter'
copyright = u'2013, Alex Gaynor and others.'

# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
# built documents.
#
# The short X.Y version.
version = '0.13.0'
# The full version, including alpha/beta/rc tags.
release = '0.13.0'

# The language for content autogenerated by Sphinx. Refer to documentation
# for a list of supported languages.
#language = None

# There are two options for replacing |today|: either, you set today to some
# non-false value, then it is used:
#today = ''
# Else, today_fmt is used as the format for a strftime call.
#today_fmt = '%B %d, %Y'

# List of patterns, relative to source directory, that match files and
# directories to ignore when looking for source files.
exclude_patterns = ['_build']

# The reST default role (used for this markup: `text`) to use for all documents.
#default_role = None

# If true, '()' will be appended to :func: etc. cross-reference text.
#add_function_parentheses = True

# If true, the current module name will be prepended to all description
# unit titles (such as .. function::).
#add_module_names = True

# If true, sectionauthor and moduleauthor directives will be shown in the
# output. They are ignored by default.
#show_authors = False

# The name of the Pygments (syntax highlighting) style to use.
pygments_style = 'sphinx'

# A list of ignored prefixes for module index sorting.
#modindex_common_prefix = []


# -- Options for HTML output ---------------------------------------------------

# The theme to use for HTML and HTML Help pages.  See the documentation for
# a list of builtin themes.
html_theme = 'default'

# Theme options are theme-specific and customize the look and feel of a theme
# further.  For a list of options available for each theme, see the
# documentation.
#html_theme_options = {}

# Add any paths that contain custom themes here, relative to this directory.
#html_theme_path = []

# The name for this set of Sphinx documents.  If None, it defaults to
# "<project> v<release> documentation".
#html_title = None

# A shorter title for the navigation bar.  Default is the same as html_title.
#html_short_title = None

# The name of an image file (relative to this directory) to place at the top
# of the sidebar.
#html_logo = None

# The name of an image file (within the static path) to use as favicon of the
# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
# pixels large.
#html_favicon = None

# Add any paths that contain custom static files (such as style sheets) here,
# relative to this directory. They are copied after the builtin static files,
# so a file named "default.css" will overwrite the builtin "default.css".
#html_static_path = ['_static']

# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
# using the given strftime format.
#html_last_updated_fmt = '%b %d, %Y'

# If true, SmartyPants will be used to convert quotes and dashes to
# typographically correct entities.
#html_use_smartypants = True

# Custom sidebar templates, maps document names to template names.
#html_sidebars = {}

# Additional templates that should be rendered to pages, maps page names to
# template names.
#html_additional_pages = {}

# If false, no module index is generated.
#html_domain_indices = True

# If false, no index is generated.
#html_use_index = True

# If true, the index is split into individual pages for each letter.
#html_split_index = False

# If true, links to the reST sources are added to the pages.
#html_show_sourcelink = True

# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
#html_show_sphinx = True

# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
#html_show_copyright = True

# If true, an OpenSearch description file will be output, and all pages will
# contain a <link> tag referring to it.  The value of this option must be the
# base URL from which the finished HTML is served.
#html_use_opensearch = ''

# This is the file name suffix for HTML files (e.g. ".xhtml").
#html_file_suffix = None

# Output file base name for HTML help builder.
htmlhelp_basename = 'django-filterdoc'


# -- Options for LaTeX output --------------------------------------------------

latex_elements = {
# The paper size ('letterpaper' or 'a4paper').
#'papersize': 'letterpaper',

# The font size ('10pt', '11pt' or '12pt').
#'pointsize': '10pt',

# Additional stuff for the LaTeX preamble.
#'preamble': '',
}

# Grouping the document tree into LaTeX files. List of tuples
# (source start file, target name, title, author, documentclass [howto/manual]).
latex_documents = [
  ('index', 'django-filter.tex', u'django-filter Documentation',
   u'Alex Gaynor and others.', 'manual'),
]

# The name of an image file (relative to this directory) to place at the top of
# the title page.
#latex_logo = None

# For "manual" documents, if this is true, then toplevel headings are parts,
# not chapters.
#latex_use_parts = False

# If true, show page references after internal links.
#latex_show_pagerefs = False

# If true, show URL addresses after external links.
#latex_show_urls = False

# Documents to append as an appendix to all manuals.
#latex_appendices = []

# If false, no module index is generated.
#latex_domain_indices = True


# -- Options for manual page output --------------------------------------------

# One entry per manual page. List of tuples
# (source start file, name, description, authors, manual section).
man_pages = [
    ('index', 'django-filter', u'django-filter Documentation',
     [u'Alex Gaynor and others.'], 1)
]

# If true, show URL addresses after external links.
#man_show_urls = False


# -- Options for Texinfo output ------------------------------------------------

# Grouping the document tree into Texinfo files. List of tuples
# (source start file, target name, title, author,
#  dir menu entry, description, category)
texinfo_documents = [
  ('index', 'django-filter', u'django-filter Documentation',
   u'Alex Gaynor and others.', 'django-filter', 'One line description of project.',
   'Miscellaneous'),
]

# Documents to append as an appendix to all manuals.
#texinfo_appendices = []

# If false, no module index is generated.
#texinfo_domain_indices = True

# How to display URL addresses: 'footnote', 'no', or 'inline'.
#texinfo_show_urls = 'footnote'

docs/conf.py
# -*- coding: utf-8 -*-
#
# django-filter documentation build configuration file, created by
# sphinx-quickstart on Mon Sep 17 11:25:20 2012.
#
# This file is execfile()d with the current directory set to its containing dir.
#
# Note that not all possible configuration values are present in this
# autogenerated file.
#
# All configuration values have a default; values that are commented out
# serve to show the default.

import sys, os

# If extensions (or modules to document with autodoc) are in another directory,
# add these directories to sys.path here. If the directory is relative to the
# documentation root, use os.path.abspath to make it absolute, like shown here.
#sys.path.insert(0, os.path.abspath('.'))

# -- General configuration -----------------------------------------------------

# If your documentation needs a minimal Sphinx version, state it here.
#needs_sphinx = '1.0'

# Add any Sphinx extension module names here, as strings. They can be extensions
# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
extensions = []

# Add any paths that contain templates here, relative to this directory.
templates_path = ['_templates']

# The suffix of source filenames.
source_suffix = '.txt'

# The encoding of source files.
#source_encoding = 'utf-8-sig'

# The master toctree document.
master_doc = 'index'

# General information about the project.
project = u'django-filter'
copyright = u'2013, Alex Gaynor and others.'

# The version info for the project you're documenting, acts as replacement for
# |version| and |release|, also used in various other places throughout the
# built documents.
#
# The short X.Y version.
version = '0.13.0'
# The full version, including alpha/beta/rc tags.
release = '0.13.0'

# The language for content autogenerated by Sphinx. Refer to documentation
# for a list of supported languages.
#language = None

# There are two options for replacing |today|: either, you set today to some
# non-false value, then it is used:
#today = ''
# Else, today_fmt is used as the format for a strftime call.
#today_fmt = '%B %d, %Y'

# List of patterns, relative to source directory, that match files and
# directories to ignore when looking for source files.
exclude_patterns = ['_build']

# The reST default role (used for this markup: `text`) to use for all documents.
#default_role = None

# If true, '()' will be appended to :func: etc. cross-reference text.
#add_function_parentheses = True

# If true, the current module name will be prepended to all description
# unit titles (such as .. function::).
#add_module_names = True

# If true, sectionauthor and moduleauthor directives will be shown in the
# output. They are ignored by default.
#show_authors = False

# The name of the Pygments (syntax highlighting) style to use.
pygments_style = 'sphinx'

# A list of ignored prefixes for module index sorting.
#modindex_common_prefix = []


# -- Options for HTML output ---------------------------------------------------

# The theme to use for HTML and HTML Help pages.  See the documentation for
# a list of builtin themes.
html_theme = 'default'

# Theme options are theme-specific and customize the look and feel of a theme
# further.  For a list of options available for each theme, see the
# documentation.
#html_theme_options = {}

# Add any paths that contain custom themes here, relative to this directory.
#html_theme_path = []

# The name for this set of Sphinx documents.  If None, it defaults to
# "<project> v<release> documentation".
#html_title = None

# A shorter title for the navigation bar.  Default is the same as html_title.
#html_short_title = None

# The name of an image file (relative to this directory) to place at the top
# of the sidebar.
#html_logo = None

# The name of an image file (within the static path) to use as favicon of the
# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
# pixels large.
#html_favicon = None

# Add any paths that contain custom static files (such as style sheets) here,
# relative to this directory. They are copied after the builtin static files,
# so a file named "default.css" will overwrite the builtin "default.css".
#html_static_path = ['_static']

# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
# using the given strftime format.
#html_last_updated_fmt = '%b %d, %Y'

# If true, SmartyPants will be used to convert quotes and dashes to
# typographically correct entities.
#html_use_smartypants = True

# Custom sidebar templates, maps document names to template names.
#html_sidebars = {}

# Additional templates that should be rendered to pages, maps page names to
# template names.
#html_additional_pages = {}

# If false, no module index is generated.
#html_domain_indices = True

# If false, no index is generated.
#html_use_index = True

# If true, the index is split into individual pages for each letter.
#html_split_index = False

# If true, links to the reST sources are added to the pages.
#html_show_sourcelink = True

# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
#html_show_sphinx = True

# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
#html_show_copyright = True

# If true, an OpenSearch description file will be output, and all pages will
# contain a <link> tag referring to it.  The value of this option must be the
# base URL from which the finished HTML is served.
#html_use_opensearch = ''

# This is the file name suffix for HTML files (e.g. ".xhtml").
#html_file_suffix = None

# Output file base name for HTML help builder.
htmlhelp_basename = 'django-filterdoc'


# -- Options for LaTeX output --------------------------------------------------

latex_elements = {
# The paper size ('letterpaper' or 'a4paper').
#'papersize': 'letterpaper',

# The font size ('10pt', '11pt' or '12pt').
#'pointsize': '10pt',

# Additional stuff for the LaTeX preamble.
#'preamble': '',
}

# Grouping the document tree into LaTeX files. List of tuples
# (source start file, target name, title, author, documentclass [howto/manual]).
latex_documents = [
  ('index', 'django-filter.tex', u'django-filter Documentation',
   u'Alex Gaynor and others.', 'manual'),
]

# The name of an image file (relative to this directory) to place at the top of
# the title page.
#latex_logo = None

# For "manual" documents, if this is true, then toplevel headings are parts,
# not chapters.
#latex_use_parts = False

# If true, show page references after internal links.
#latex_show_pagerefs = False

# If true, show URL addresses after external links.
#latex_show_urls = False

# Documents to append as an appendix to all manuals.
#latex_appendices = []

# If false, no module index is generated.
#latex_domain_indices = True


# -- Options for manual page output --------------------------------------------

# One entry per manual page. List of tuples
# (source start file, name, description, authors, manual section).
man_pages = [
    ('index', 'django-filter', u'django-filter Documentation',
     [u'Alex Gaynor and others.'], 1)
]

# If true, show URL addresses after external links.
#man_show_urls = False


# -- Options for Texinfo output ------------------------------------------------

# Grouping the document tree into Texinfo files. List of tuples
# (source start file, target name, title, author,
#  dir menu entry, description, category)
texinfo_documents = [
  ('index', 'django-filter', u'django-filter Documentation',
   u'Alex Gaynor and others.', 'django-filter', 'One line description of project.',
   'Miscellaneous'),
]

# Documents to append as an appendix to all manuals.
#texinfo_appendices = []

# If false, no module index is generated.
#texinfo_domain_indices = True

# How to display URL addresses: 'footnote', 'no', or 'inline'.
#texinfo_show_urls = 'footnote'


# see:
# https://github.com/snide/sphinx_rtd_theme#using-this-theme-locally-then-building-on-read-the-docs
on_rtd = os.environ.get('READTHEDOCS', None) == 'True'

# only import and set the theme if we're building docs locally
if not on_rtd:
    import sphinx_rtd_theme

    html_theme = 'sphinx_rtd_theme'
    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]

docs/conf.py
diff --git a/docs/conf.py b/docs/conf.py
index e6d265019..1db554fa7 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -240,3 +240,15 @@
 
 # How to display URL addresses: 'footnote', 'no', or 'inline'.
 #texinfo_show_urls = 'footnote'
+
+
+# see:
+# https://github.com/snide/sphinx_rtd_theme#using-this-theme-locally-then-building-on-read-the-docs
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+# only import and set the theme if we're building docs locally
+if not on_rtd:
+    import sphinx_rtd_theme
+
+    html_theme = 'sphinx_rtd_theme'
+    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
diff --git a/docs/ref/filters.txt b/docs/ref/filters.txt
index 8a7ca8ec1..cfea16824 100644
--- a/docs/ref/filters.txt
+++ b/docs/ref/filters.txt
@@ -460,10 +460,15 @@ database.  So if in the DB for the given field you have values of 5, 7, and 9
 each of those is present as an option.  This is similar to the default behavior
 of the admin.
 
+.. _base-in-filter:
+
 ``BaseInFilter``
 ~~~~~~~~~~~~~~~~
 
-This is a base class used for generating IN lookup filters. Values are expected to be comma separated.
+This is a base class used for creating IN lookup filters. It is expected that
+this filter class is used in conjunction with another filter class, as this
+class **only** validates that the incoming value is comma-separated. The secondary
+filter is then used to validate the individual values.
 
 Example. ::
 
@@ -488,7 +493,9 @@ Example. ::
 ``BaseRangeFilter``
 ~~~~~~~~~~~~~~~~~~~
 
-This is a base class used for generating RANGE lookup filters. The base class expects two values two, separated by a comma.
+This is a base class used for creating RANGE lookup filters. It behaves
+identically to ``BaseInFilter`` with the exception that it expects only two
+comma-separated values.
 
 Example. ::
 
diff --git a/docs/usage.txt b/docs/usage.txt
index 10609fcc5..0ad4ede7a 100644
--- a/docs/usage.txt
+++ b/docs/usage.txt
@@ -79,7 +79,19 @@ For Django version 1.8, transformed expressions are not supported.
 
 .. _`lookup reference`: https://docs.djangoproject.com/en/dev/ref/models/lookups/#module-django.db.models.lookups
 
-While both of these fields are optional, it is recommended that you specify
+
+Common declarative problems
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Below are some of the common problem that occur when declaring filters. It is
+recommended that you do read this as it provides a more complete understanding
+on how filters work.
+
+
+Filter ``name`` and ``lookup_expr`` not configured
+""""""""""""""""""""""""""""""""""""""""""""""""""
+
+While ``name`` and ``lookup_expr`` are optional, it is recommended that you specify
 them. By default, if ``name`` is not specified, the filter's name on the
 filterset class will be used. Additionally, ``lookup_expr`` defaults to
 ``exact``. The following is an example of a misconfigured price filter::
@@ -92,14 +104,56 @@ lookup type. Under the hood, this will incorrectly be resolved as::
 
     Produce.objects.filter(price__gt__exact=value)
 
-.. note::
+The above will most likely generate a ``FieldError``. The correct configuration
+would be::
+
+    class ProductFilter(django_filters.FilterSet):
+        price__gt = django_filters.NumberFilter(name='price', lookup_expr='gt')
+
+
+Missing ``lookup_expr`` for text search filters
+"""""""""""""""""""""""""""""""""""""""""""""""
+
+It's quite common to forget to set the lookup expression for :code:`CharField`
+and :code:`TextField` and wonder why a search for "foo" does not return results
+for "foobar". This is because the default lookup type is ``exact``, but you
+probably want to perform  an ``icontains`` lookup.
 
-    It's quite common to forget to set the lookup expression for
-    :code:`CharField` and :code:`TextField` and wonder why a search for "foo"
-    does not return results for "foobar". This is because the default lookup
-    type is `exact`, but you probably want to perform  an `icontains` lookup.
 
-For more information on additional arguments, see :ref:`core-arguments`.
+Filter and lookup expression mismatch (in, range, isnull)
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+It's not always appropriate to directly match a filter to its model field's
+type, as some lookups expect different types of values. This is a commonly
+found issue with ``in``, ``range``, and ``isnull`` lookups. Let's look
+at the following product model::
+
+    class Product(models.Model):
+        category = models.ForeignKey(Category, null=True)
+
+Given that ``category`` is optional, it's reasonable to want to enable a search
+for uncategorized products. The following is an incorrectly configured
+``isnull`` filter::
+
+    class ProductFilter(django_filters.FilterSet):
+        uncategorized = django_filters.NumberFilter(name='category', lookup_expr='isnull')
+
+So what's the issue? While the underlying column type for ``category`` is an
+integer, ``isnull`` lookups expect a boolean value. A ``NumberFilter`` however
+only validates numbers. Filters are not `'expression aware'` and won't change
+behavior based on their ``lookup_expr``. You should use filters that match the
+data type of the lookup expression `instead` of the data type underlying model
+field. The following would correctly allow you to search for both uncategorized
+products and products for a set of categories::
+
+    class NumberInFilter(django_filters.BaseInFilter, django_filters.NumberFilter):
+        pass
+
+    class ProductFilter(django_filters.FilterSet):
+        categories = NumberInFilter(name='category', lookup_expr='in')
+        uncategorized = django_filters.BooleanFilter(name='category', lookup_expr='isnull')
+
+More info on constructing IN and RANGE csv :ref:`filters <base-in-filter>`.
 
 
 Generating filters with Meta.fields

Improve docs on common pitfalls
Referencing this [discussion](https://github.com/carltongibson/django-filter/issues/394#issuecomment-202942471), docs could better explain some common misunderstandings about filter validation and data shape for various query expressions. eg, a CharFilter validates and outputs a single string, which is incompatible with 'in' lookups as it expects a list of strings. 

[This](https://github.com/carltongibson/django-filter/blob/v0.13/docs/usage.txt#L82-L100) section would be a good spot to expand on it. 

