Text Presentation Sequences

[DanielGekeler]

Many emojis can be combined with VARIATION SELECTOR-15 to appear as a text variant. This forms a ED-8a text presentation sequence defined in UTS 51.
Example: ⏳ -> ⏳︎

The definition of ED-8a states that the only valid sequences are those listed in emoji-variation-sequences.txt. These are also included in <standardized-variants> of UCD XML.

Let's get to the issue: 🎶 U+1F3B6 MULTIPLE MUSICAL NOTES
Codepoints.net states that it can be combined with VS15 to get this: 🎶︎ even though it isn't listed in emoji-variation-sequences.txt.
This character combined with VS15 seems to be widely supported even though it does not adhere to UTS 51.

How does Codepoints.net decide to show this notice?

[Boldewyn]

Thanks for the report and sorry for the late response!

Currently, the decision is made based on the EPres property in the UCD XML file. So, based on this part of TR 51, that should be the correct:

https://github.com/Codepoints/Codepoints.net/blob/main/codepoints.net/views/partials/codepoint-description.php#L359

The question now is, whether the emoji-variation-sequences.txt file is incomplete or the Emoji_Presentation property is wrongfully set to false. Hard to tell, actually. I’m a bit inclined to put the blame on the emoji-variation-sequences.txt file, since it is not obvious, why the whole range 1F3?? has the emoji property set but only a part of it has the variation possibility.

Maybe the Unicode mailing list would be a good place to ask further. On my end, I’m a bit torn to change anything, since obviously U+1F3B6 does react to a VS15, and the EPres property from the UCD XML file tells me that that’s OK. (But I’m happy to stand corrected, if I missed something.)