Added doc about setting up languages on registration.

site/docs/v1/tech/guides/advanced-registration-forms.adoc

@@ -18,6 +18,7 @@ Advanced registration forms let you build multi-step custom registration and adm
 * <<Editing User Data In the Admin UI>>
 * <<Using the API to Manage Forms>>
 * <<Consents>>
+* <<Email Localization>>
 * <<Form Fields and Validation>>
 * <<Special Considerations>>
 
@@ -627,6 +628,20 @@ The consent field will have a name automatically generated based on the consent
 consents['dd35541d-e725-4487-adba-5edbd3680fb8']=I consent to sharing my data with affiliated companies
 ```
 
+== Email Localization
+
+Emails are localized based on the user preferred language attributes. link:/docs/v1/tech/core-concepts/localization-and-internationalization[Learn more here about the different ways FusionAuth localizes content].
+
+Using advanced registration forms, you can set this attribute on registration. FusionAuth will then localize any initial emails, such as a password setup or email verification email.
+
+To do so, add a custom field to your form setting the [field]#user.preferredLanguages# field. You can use the default one that ships with FusionAuth, as below.
+
+image::guides/advanced-registration-forms/setup-locale-selection.png[Add locale choice to registration form.,width=1200]
+
+This will build a select box with a list of all supported locales. If you'd prefer to limit it to a certain subset, copy the default field and edit the allowed values.
+
+You may also add this as a hidden field and set it via JavaScript if you'd rather not display the dropdown.
+
 == Form Fields and Validation
 
 Making sure user registration data meets your quality requirements is important. FusionAuth provides multiple ways to validate user input during the registration process.
@@ -706,6 +721,7 @@ Assume you've enabled the Facebook identity provider and allowed for registratio
 
 After a user signs up with Facebook, they'll be dropped back into the registration flow on the second step. They'll be required to complete the registration from from the second step onward before they are fully registered.
 
+
 ++++
 {% capture relatedTag %}feature-advanced-registration-forms{% endcapture %}
 {% include _doc-related-posts.liquid %}