IssueTracker

Steps to reproduce:

1. Have an active SIM or eSIM in your mobile device. It may be helpful, for reproduction purposes, to have two SIMs active in the device; it's possible that Dialer and Messages don't display this information unless there are 2+ SIMs.
2. Settings > Network & Internet > SIMs. Click the SIM you want to modify.
3. Click the "Edit" (pencil) icon at the top-right.
4. The default 'Name' will be supplied by the carrier. For example, if you are on US Mobile's AT&T MVNO, the value will be "Dark Star". Change this value to something you prefer, and click Save.

Expected results:

Your user-defined SIM name should be used everywhere the SIM and the mobile network it provides are referred to.

Actual results:

The names are used inconsistently:

• The user-defined name appears when describing the SIM being used in Google Messages and in the Dialer.
• The carrier-defined "Mobile Network" name appears in the Notification Drawer when showing which networks are active and their signal strength.

I think it's important to recognize that, while engineers distinguish between a SIM and a mobile network, ordinary users do not. The user-defined custom name should be used everywhere either that SIM or its mobile network are referred to.