  
  from .messages import (CheckMessage,
          Debug, Info, Warning, Error, Critical,
          DEBUG, INFO, WARNING, ERROR, CRITICAL)
  from .registry import register, run_checks, tag_exists
  
  # Import these to force registration of checks
  import django.core.checks.compatibility.django_1_6_0  # NOQA
  import django.core.checks.model_checks  # NOQA
  
 
</s> remove from .. import Warning, register
 </s> add from .. import Warning, register, Tags </s> remove from . import Error, register
 </s> add from . import Error, Tags, register </s> remove @register('compatibility')
 </s> add @register(Tags.compatibility) </s> remove @register('models')
 </s> add @register(Tags.models) </s> remove @register('models', 'signals')
 </s> add @register(Tags.models, Tags.signals)
from .registry import register, run_checks, tag_exists, Tags
  
  from .messages import (CheckMessage,
          Debug, Info, Warning, Error, Critical,
          DEBUG, INFO, WARNING, ERROR, CRITICAL)
from .registry import register, run_checks, tag_exists, Tags
  
  # Import these to force registration of checks
  import django.core.checks.compatibility.django_1_6_0  # NOQA
  import django.core.checks.model_checks  # NOQA
  
keep keep keep keep replace keep keep keep keep keep
 Fixed #22195 -- Used constants to define built-in tags for check framework.

Thanks Elvard for the patch. 
django/core/checks/__init__.py