Includes all error definition in the API docs

docs/api.rst

@@ -53,7 +53,31 @@ Python Error Representations
 Error Codes
 ~~~~~~~~~~~
 
-These errors are used as :attr:`~cerberus.errors.ValidationError.code`.
+Its :attr:`code` attribute uniquely identifies an
+:class:`~cerberus.errors.ErrorDefinition` that is used a concrete error's
+:attr:`~cerberus.errors.ValidationError.code`.
+Some codes are actually reserved to mark a shared property of different errors.
+These are useful as bitmasks while processing errors. This is the list of the
+reserved codes:
+
+============= ======== === ==================================================
+``0110 0000`` ``0x60`` 96 An error that occurred during normalization.
+``1000 0000`` ``0x80`` 128 An error that contains child errors.
+``1001 0000`` ``0x90`` 144 An error that was emitted by one of the *of-rules.
+============= ======== === ==================================================
+
+None of these bits in the upper nibble must be used to enumerate error
+definitions, but only to mark one with the associated property.
+
+.. important::
+
+ Users are advised to set bit 8 for self-defined errors. So the code
+ ``0001 0000 0001`` / ``0x101`` would the first in a domain-specific set of
+ error definitions.
+
+
+This is a list of all error defintions that are shipped with the
+:mod:`~cerberus.errors` module:
 
 .. include:: includes/error-codes.rst
 

docs/includes/generate.py

@@ -23,7 +23,7 @@ def load_module_members(name, path):
 error_type = errors_module['ErrorDefinition']
 error_definitions = []
 for name, member in errors_module.items():
- if not isinstance(member, error_type) or member.rule is None:
+ if not isinstance(member, error_type):
  continue
  error_definition = SimpleNamespace(**member._asdict())
  error_definition.name = name