[crooked-v]

Discord and Blizzard both use a unique numerical ID as the true source of identity (your name displays like "Mr. Bob#1234", but only the "1234" part is actually important), while using email for logging in. The email and the display name can both be changed at any time.

[kevin_b_er]

The 1234 part changes too and if you pay for the premium service, called Discord Nitro, you can set it it to whatever you want instead of a random value. Its only purpose is to prevent name collisions.

In many fashions, the account is identified by a "snowflake", a 64-bit ID space that every user, every guild/"server", every channel, and every message has.

Its described here and is the only permanent identity on the account, since everything else can be changed. The identity used to @ is transient and can change at any time, but the client, the API, and the myraid of bots written for Discord know the real identity is the snowflake ID.

https://discord.com/developers/docs/reference#snowflakes

At what point is it no longer an identity and instead a database identifier? That's a good question.

[csande17]

I'm pretty sure the ID that Discord and Blizzard use as the "true" source of identity (as in, the key they store in the database to keep track of who's on your buddy list) is different from the "#1234" number used to disambiguate people with the same username.

In particular, that number is only four base-10 digits long, and I'm pretty sure there are more than 10,000 people in the world who have ever played Hearthstone.

[tonyarkles]

And ICQ! While AIM was letting people choose usernames, ICQ looked deep into your soul and assigned you an ID based on the order in which you joined :)

[mey]

Still remember my ICQ number even though it got account hijacked LONG ago.