Fixed #21397 -- Re-added flexibility to TypedChoiceField coercion

Thanks Elec for the report and Simon Charette for the review.

1 files changed, 3 insertions, 1 deletions

diff --git a/docs/ref/forms/fields.txt b/docs/ref/forms/fields.txt
index 81b65d04d4..f2cd122526 100644
--- a/docs/ref/forms/fields.txt
+++ b/docs/ref/forms/fields.txt
@@ -375,7 +375,9 @@ For each field, we describe the default widget used if you don't specify
 
         A function that takes one argument and returns a coerced value. Examples
         include the built-in ``int``, ``float``, ``bool`` and other types. Defaults
-        to an identity function.
+        to an identity function. Note that coercion happens after input
+        validation, so it is possible to coerce to a value not present in
+        ``choices``.
 
     .. attribute:: empty_value