--- /dev/null
+/// @file FIRUserPropertyNames.h
+///
+/// Predefined user property names.
+///
+/// A UserProperty is an attribute that describes the app-user. By supplying UserProperties, you can
+/// later analyze different behaviors of various segments of your userbase. You may supply up to 25
+/// unique UserProperties per app, and you can use the name and value of your choosing for each one.
+/// UserProperty names can be up to 24 characters long, may only contain alphanumeric characters and
+/// underscores ("_"), and must start with an alphabetic character. UserProperty values can be up to
+/// 36 characters long. The "firebase_", "google_", and "ga_" prefixes are reserved and should not
+/// be used.
+
+#import <Foundation/Foundation.h>
+
+/// The method used to sign in. For example, "google", "facebook" or "twitter".
+static NSString *const kFIRUserPropertySignUpMethod
+ NS_SWIFT_NAME(AnalyticsUserPropertySignUpMethod) = @"sign_up_method";