diff --git a/dropbox/openid.py b/dropbox/openid.py
index f600979..47723ed 100644
--- a/dropbox/openid.py
+++ b/dropbox/openid.py
@@ -128,18 +128,24 @@ def _process_custom_annotations(self, annotation_type, field_path, processor):
 class UserInfoResult(bb.Struct):
     """
     :ivar UserInfoResult.family_name:
-        Last name of user.
+        Last name of the user.
     :ivar UserInfoResult.given_name:
-        First name of user.
+        First name of the user.
     :ivar UserInfoResult.email:
-        Email address of user.
+        The user's email address. Be aware it's possible that the user has since
+        lost access to their email. Note: email is not a unique or stable
+        identifier for a Dropbox account. Users can change their email, and
+        emails can be reused by different accounts. Apps should not use email as
+        a key for account identification; use ``sub`` instead.
     :ivar UserInfoResult.email_verified:
-        If user is email verified.
+        If the user's email address is verified.
     :ivar UserInfoResult.iss:
-        Issuer of token (in this case Dropbox).
+        Issuer of the token (in this case Dropbox).
     :ivar UserInfoResult.sub:
         An identifier for the user. This is the Dropbox account_id, a string
-        value such as dbid:AAH4f99T0taONIb-OurWxbNQ6ywGRopQngc.
+        value such as dbid:AAH4f99T0taONIb-OurWxbNQ6ywGRopQngc. The account_id
+        is a unique and stable identifier for a Dropbox account, suitable for
+        use as a key in authentication and account management.
     """
 
     __slots__ = [
diff --git a/dropbox/users.py b/dropbox/users.py
index 7390278..b29d8b6 100644
--- a/dropbox/users.py
+++ b/dropbox/users.py
@@ -23,13 +23,16 @@ class Account(bb.Struct):
     queried and the user making the query.
 
     :ivar Account.account_id:
-        The user's unique Dropbox ID.
+        The user's unique and stable Dropbox ID.
     :ivar Account.name:
         Details of a user's name.
     :ivar Account.email:
         The user's email address. Do not rely on this without checking the
         ``email_verified`` field. Even then, it's possible that the user has
-        since lost access to their email.
+        since lost access to their email. Note: email is not a unique or stable
+        identifier for a Dropbox account. Users can change their email, and
+        emails can be reused by different accounts. Apps should not use email as
+        a key for account identification; use ``account_id`` instead.
     :ivar Account.email_verified:
         Whether the user has verified their email address.
     :ivar Account.profile_photo_url:
diff --git a/spec b/spec
index 22a3058..404afad 160000
--- a/spec
+++ b/spec
@@ -1 +1 @@
-Subproject commit 22a3058f8c5594956fcded8d120700475c2ec9d7
+Subproject commit 404afad5c508a45ea9004c9d8c0cd4a56f0fbf22