2

Under:

System Preferences > Users & Groups > Advanced Options > Aliases:

There are 2 lines. One is my Apple ID. The second is in the form

com.apple.idms.GUID

What is the significance of these fields?

I do not have my Apple ID set to login my computer.

1

A user name alias functions as a simple way to create a shorthand version of an account name.

For example, if a users full account name is “Buscar웃SD” (which would be difficult to type every time to log in), one could setup an alias as “BSD” and just login with the shortened version instead.

0

Ruskes answer is correct historically. I believe it is still true, but nowadays anything in advanced preferences must be approached with great caution.

I think it's might be safe to add an additional alias there, but be careful about removing any. It's not clear what the com.apple.idms.appleid.prd.GUID or similar Aliases mean, but a 2017 Apple Discussion response suggests some are related to Apple Store identifiers particularly when a user's Apple Store ID differs from their iCloud ID. When I browse Mojave's Diretory Uility.app's Directory Editor for my user account the RecordName keyvalue pair shows both my macOS name and a string of the form com.apple.idms.appleid.prd....

I think as Apple has integrated macOS with their Cloud services and legacy problems with user identifiers they've extended the use of Users & Groups Aliases to bind together identifiers on different services.

In 2019 we should probably forget that "Advanced Options" exists at all (except perhaps for changing one's shell)

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .