Fixed #35870 -- Made blank choice label in forms more accessible.

Added new constant django.db.models.fields.BLANK_CHOICE_LABEL for
an accessible and translatable blank choice label in forms.
Deprecated django.db.models.fields.BLANK_CHOICE_DASH constant.
Added the immediately deprecated transitional setting
USE_BLANK_CHOICE_DASH.

Co-Authored-By: Marijke Luttekes <mail@marijkeluttekes.dev>

3 files changed, 28 insertions, 5 deletions

diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index e248b70ba3..a7ec41bf75 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -15,6 +15,7 @@ from django.core import checks, exceptions, validators
 from django.db import connection, connections, router
 from django.db.models.constants import LOOKUP_SEP
 from django.db.models.query_utils import DeferredAttribute, RegisterLookupMixin
+from django.db.models.utils import get_blank_choice_label
 from django.db.utils import NotSupportedError
 from django.utils import timezone
 from django.utils.choices import (
@@ -39,7 +40,9 @@ from django.utils.translation import gettext_lazy as _
 
 __all__ = [
     "AutoField",
+    # RemovedInDjango70Warning
     "BLANK_CHOICE_DASH",
+    "BLANK_CHOICE_LABEL",
     "BigAutoField",
     "BigIntegerField",
     "BinaryField",
@@ -81,9 +84,13 @@ class NOT_PROVIDED:
     pass
 
 
-# The values to use for "blank" in SelectFields. Will be appended to the start
-# of most "choices" lists.
+# RemovedInDjango70Warning: From Django 6.1, the values to use for "blank"
+# in SelectFields will be defined by the below BLANK_CHOICE_LABEL constant.
+# Will be appended to the start of most "choices" lists.
+# BLANK_CHOICE_DASH is still available as a constant in Django 6.1.
 BLANK_CHOICE_DASH = [("", "---------")]
+# This allows any app's ready() method to overwrite BLANK_CHOICE_LABEL.
+BLANK_CHOICE_LABEL = _("- Select an option -")
 
 
 def _load_field(app_label, model_name, field_name):
@@ -1088,7 +1095,7 @@ class Field(RegisterLookupMixin):
     def get_choices(
         self,
         include_blank=True,
-        blank_choice=BLANK_CHOICE_DASH,
+        blank_choice=None,
         limit_choices_to=None,
         ordering=(),
     ):
@@ -1096,6 +1103,8 @@ class Field(RegisterLookupMixin):
         Return choices with a default blank choices included, for use
         as <select> choices for this field.
         """
+        if blank_choice is None:
+            blank_choice = [("", get_blank_choice_label())]
         if self.choices is not None:
             if include_blank:
                 return BlankChoiceIterator(self.choices, blank_choice)
diff --git a/django/db/models/fields/reverse_related.py b/django/db/models/fields/reverse_related.py
index e6c2525115..df50ba436f 100644
--- a/django/db/models/fields/reverse_related.py
+++ b/django/db/models/fields/reverse_related.py
@@ -13,7 +13,7 @@ from django.core import exceptions
 from django.utils.functional import cached_property
 from django.utils.hashable import make_hashable
 
-from . import BLANK_CHOICE_DASH
+from ..utils import get_blank_choice_label
 from .mixins import FieldCacheMixin
 
 
@@ -172,7 +172,7 @@ class ForeignObjectRel(FieldCacheMixin):
     def get_choices(
         self,
         include_blank=True,
-        blank_choice=BLANK_CHOICE_DASH,
+        blank_choice=None,
         limit_choices_to=None,
         ordering=(),
     ):
@@ -183,6 +183,8 @@ class ForeignObjectRel(FieldCacheMixin):
         Analog of django.db.models.fields.Field.get_choices(), provided
         initially for utilization by RelatedFieldListFilter.
         """
+        if blank_choice is None:
+            blank_choice = [("", get_blank_choice_label())]
         limit_choices_to = limit_choices_to or self.limit_choices_to
         qs = self.related_model._default_manager.complex_filter(limit_choices_to)
         if ordering:
diff --git a/django/db/models/utils.py b/django/db/models/utils.py
index c6cb5ef165..7f38bd7afb 100644
--- a/django/db/models/utils.py
+++ b/django/db/models/utils.py
@@ -67,3 +67,15 @@ class AltersData:
                         break
 
         super().__init_subclass__(**kwargs)
+
+
+# RemovedInDjango70Warning: At the end of the deprecation, remove this function
+# and use .fields.BLANK_CHOICE_LABEL directly instead.
+def get_blank_choice_label():
+    from django.conf import settings
+
+    from .fields import BLANK_CHOICE_DASH, BLANK_CHOICE_LABEL
+
+    if settings.USE_BLANK_CHOICE_DASH:
+        return BLANK_CHOICE_DASH[0][1]
+    return BLANK_CHOICE_LABEL