Don't get it. What would you have expected?

To: "MarkTraceur (WMF)" <mholmquist@wikimedia.org>

instead? What kind of "syntax designates a comment" by which definition?

I clarified the bug summary to what I think Mark was getting at.

Basically. The "(WMF)" in the raw header got taken out of the display, because it's a comment based on http://www.ietf.org/rfc/rfc2822.txt

I'd like the message body to include the account name for clarity.

Sounds like a bug with "(WMF)" accounts names to me :>

Confirmed the bug - username's part in parentheses got dropped when displayed in To header of a received email.

e.g. ET (ABC) will become
to: ET <etonkovidova@wikimedia.org>

@jmatazzoni , @Pginer-WMF Any preference for how to include the user account name in the user-rights notification messages?

One option is to replace you by the account name and maybe bold it.

Your user rights were changed. You have been added to: ‪Add-1‬, ‪Add-2‬. You are no longer a member of: ‪Remove-1‬, ‪Remove-2‬.

Would become

Your user rights were changed. MyUsername (WMF) has been added to: ‪Add-1‬, ‪Add-2‬. MyUsername (WMF) is no longer a member of: ‪Remove-1‬, ‪Remove-2‬.

In T71981#740262, @MarkTraceur wrote:

Basically. The "(WMF)" in the raw header got taken out of the display, because it's a comment based on http://www.ietf.org/rfc/rfc2822.txt

I'd like the message body to include the account name for clarity.

Is there a way to escape the string? I'm not familiar with this particular format, but I'd expect some way to indicate text is literal. Using quotes was suggested in this discussion about brackets disappearing on emails which I'm not sure how closely related is to our case.

Related tickets: T90067 T136770 T90067

I think it's useful to put in the body regardless. People might not know to check the To (they know they received the email after all) even if the escaping works.

Filed the To issue as T158269: Escape round parentheses so they properly show in To

Discussed in Growth team triage meeting today. @Catrope is going to create a task for redesigning Notification emails, and then this task could get added as a subtask of that. Once we have the overall picture of what needs to get done, we could look at scheduling the work for this particular feature.

To resolve this task, I propose to change the following messages:

"notification-header-user-rights-add-only": "{{GENDER:$4|Your}} user rights were {{GENDER:$1|changed}}. You have been added to: $2.",
"notification-header-user-rights-remove-only": "{{GENDER:$4|Your}} user rights were {{GENDER:$1|changed}}. You are no longer a member of: $2.",
"notification-header-user-rights-add-and-remove": "{{GENDER:$6|Your}} user rights were {{GENDER:$1|changed}}. You have been added to: $2. You are no longer a member of: $4.",
"notification-header-user-rights-expiry-change": "The expiry of {{GENDER:$4|your}} membership in the following {{PLURAL:$3|group|groups}} has been {{GENDER:$1|changed}}: $2.",

to this:

"notification-header-user-rights-add-only": "$4, {{GENDER:$4|your}} user rights were {{GENDER:$1|changed}}. You have been added to: $2.",
"notification-header-user-rights-remove-only": "$4, {{GENDER:$4|your}} user rights were {{GENDER:$1|changed}}. You are no longer a member of: $2.",
"notification-header-user-rights-add-and-remove": "$6, {{GENDER:$6|your}} user rights were {{GENDER:$1|changed}}. You have been added to: $2. You are no longer a member of: $4.",
"notification-header-user-rights-expiry-change": "$4, the expiry of {{GENDER:$4|your}} membership in the following {{PLURAL:$3|group|groups}} has been {{GENDER:$1|changed}}: $2.",

Would that be sufficient, given that T121067 is apparently fixed as well?

@daniel's solution looks good to me. Is this a patch-welcome task?

I think the more worrying issue here, which is not fixed by the message change, is that the header is generated incorrectly - it should have been escaped:

To: "MarkTraceur (WMF)" <mholmquist@wikimedia.org>

(Maybe that should be a separate task?)