Why does this work? friendly_name: l❤️velace

pure by accident (my daughters iPhone have names with hundreds of emoji…) I stumbled on this in a device_trackers name:

name: “Name\U0001F919\U0001F3FB❤️”

which shows i my frontend as:

53

made me want to try this for Lovelace and replace the o with a heart:

54

made by customizing a friendly_name for

weblink.lovelace:
  friendly_name: '\U0001F3FB❤️' 

its not possible to get it to show correctly so I made a screenshot:

01

apparently the | formats the heart? What is this, and why does it work? Its not an alt-code is it: https://www.alt-codes.net/heart_alt_code.php

seems to be originated here?

which is kind of nice, though Id like to understand how it works in HA and rather have it not use a V after the heart

So does your daughter have an app that replaces text with emojis? That would be the first place I look.

no, they just enter emojis in just about everything…
aparently, if you do that in your phone’s name, the bluetooth tracker see that and shows it like posted in known_devices.

I simpt copied that bit in the L❤️velace link and it showed. Like here.