Hello Marcel, Documentation does not indicate restrictions on user ID's, you may check "Getting profile information" page <https://developers.google.com/identity/sign-in/web/people> for related details. You can choose IDs or pattern for IDs that might correlate to the old App Engine IDs. This might not prove of any advantage in the end, as in Google Identity Platform you are not supposed to use these IDs to validate user log-ins. Same applies to emails and email variants such as joh...@gmail.com and jo...@gmail.com. You may check the "Send the ID token to your server" on the "Authenticate with a backend server" page <https://developers.google.com/identity/sign-in/web/backend-auth>.
To reply to your second question, on the same documentation page you'll notice that the get method for email profile.getEmail() does not allow for multiple email values within the same user identity profile. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/5c683983-4761-4757-b4dd-e1414751e918%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
