Hashing with sha256 when sending user_data to GA4, Google ads, etc

Question

tl;dr: Should there be a sha256_ prefix to city, regon, postal code, country, and should I hash them or not?

---- details I am wondering wether google doesn't consider city, region and postal code a sensitive information or the docs are incomplete. Judging by the second example, I don't need to hash even street address. And yet I believe I should hash everything... [Using smarty in the examples]

                gtag('set', 'user_data', {
                    "sha256_email_address": "{hash('sha256', $order_info.email)}",
                    "address": {
                        "sha256_first_name": "{hash('sha256', $order_info.firstname)}",
                        "sha256_last_name": "{hash('sha256', $lastname)}",
                        "sha256_street": "{hash('sha256', $address)}",
                        "sha256_city":"{hash('sha256', $city)}",
                        "sha256_region":"{hash('sha256', $country)}",
                        "sha256_postal_code": "{hash('sha256', $zipcode)}",
                        "sha256_country": "{hash('sha256', $country)}"
                    }
                });

**Resources: ** https://support.google.com/analytics/answer/14171598 https://developers.google.com/analytics/devguides/collection/ga4/uid-data

"sha256_city":"{hash('sha256', $city)}", vs "city":"{hash('sha256', $city)}", vs "city":"{$city}",

Answer 1

The documentation shows this clear example (in node.js):

user_data: {
  sha256_email_address: yourEmailSha256Variable,
  sha256_phone_number: yourPhoneSha256Variable,
  address: {
    sha256_first_name: yourFirstNameSha256Variable,
    sha256_last_name: yourLastNameSha256Variable,
    sha256_street: yourStreetAddressSha256Variable,
    city: yourCityVariable,
    region: yourRegionVariable,
    postal_code: yourPostalCodeVariable,
    country: yourCountryVariable
  }
}

The description of user_data.address[].city is

City for the address of the user. Normalized as such:

• remove digits and symbol characters
• lowercase
• remove leading and trailing spaces

So the answer about your question is:

"city":"{$city}"

https://developers.google.com/analytics/devguides/collection/ga4/uid-data?hl=en