diff --git a/docs/8.0/ayanova/docs/ay-customize.md b/docs/8.0/ayanova/docs/ay-customize.md
index 30090393..c230774a 100644
--- a/docs/8.0/ayanova/docs/ay-customize.md
+++ b/docs/8.0/ayanova/docs/ay-customize.md
@@ -86,6 +86,12 @@ We have a [Guided tour for custom fields](tour-bizadmin-form-custom-fields.md) a
 
 If you change the data type of a custom field after data has been entered AyaNova will do it's best to work with that change but it's not recommended. It's better to simply hide the former custom control and show a new one with the new data type.
 
+#### Checkbox custom fields on existing records
+
+When a `True / False` checkbox custom field is enabled, records that already existed have no value for it at all, neither true nor false. In a [data table](ay-start-form-data-tables.md) column for that field those records show nothing (an "indeterminate" value).
+
+Once the checkbox is set or cleared on a record and the record is saved, the data table shows true or false for it like any other record.
+
 ### Changing the title of fields
 
 To change the label text displayed to the User above any field (not just custom fields), edit any [translations](adm-translations.md) in use for that field's translation key. The internal Translation Key for each field is displayed in the Customize form beneath the current translation of that field's title to simplify finding which translation item needs to be changed.