vCard 4.0 looks stable to me now.

vCard 4 also has the concept of lists so we could drop our "VLIST".

Example:

 BEGIN:VCARD
     VERSION:4.0
     KIND:group
     FN:The Doe family
     MEMBER:urn:uuid:03a0e51f-d1aa-4385-8a53-e29025acd8af
     MEMBER:urn:uuid:b8767877-b4a1-4c70-9acc-505d3819e519
     END:VCARD
     BEGIN:VCARD
     VERSION:4.0
     FN:John Doe
     UID:urn:uuid:03a0e51f-d1aa-4385-8a53-e29025acd8af
     END:VCARD
     BEGIN:VCARD
     VERSION:4.0
     FN:Jane Doe
     UID:urn:uuid:b8767877-b4a1-4c70-9acc-505d3819e519
     END:VCARD
     BEGIN:VCARD
     VERSION:4.0
     KIND:group
     FN:Funky distribution list
     MEMBER:mailto:subscriber1@example.com
     MEMBER:xmpp:subscriber2@example.com
     MEMBER:sip:subscriber3@example.com
     MEMBER:tel:+1-418-555-5555
     END:VCARD

+1 for vCard 4.0

I recently found a number of field mapping problems between SOGo and eM Client relating to Address Book / Contacts. I believe if vCard 4.0 were properly implemented by both SOGo and eM Client, then they might be resolved without further problems. I have made a feature request to eM Client on this, but I'm not sure how far their forum system carries such things.

Other than this, SOGo is doing me quite nicely, thank you.

+1

I would love to have the possibility to sync more fields, preferably all that can be entered&displayed on Thunderbird.
Syncing smartphone<->CardDAV server is working fine, but CardDAV server<-> Thunderbird drops many fields.

I've noticed missing REV property in SOGo vCard.
This property could be helpful for synchronization of Contacts, in combination with UID - and it can help to avoid duplicated entries in Address Book?

when i use apple address book groups are defines as
they are synchronized, so i can use them on my macbook and iMac.
but they are not shown in SOGo. SOGo still uses list.
If you update card please support Apple Address Book Format for groups

BEGIN:VCARD VERSION:3.0
PRODID:-//Apple Inc.//AddressBook 11.0//EN
N:Neue Gruppe
FN:Neue Gruppe
X-ADDRESSBOOKSERVER-KIND:group
X-ADDRESSBOOKSERVER-MEMBER:urn:uuid:123-456-789-000.vcf
X-ADDRESSBOOKSERVER-MEMBER:urn:uuid:234-889-678-000.vcf
REV:2018-05-10T10:10:57Z
UID:97abcde...
END:VCARD

+1

Support for vCard 4.0 would be nice - are there already any plans or timetables?

vCard 4.0 allows to specify a date without a year: https://datatracker.ietf.org/doc/html/rfc6350#section-4.3.1
For example, the date of this post would be:
--0804
This allows to add birthday to remember to greet the person without knowing the age of the person.

There is no need to wait for vCard 4.0 becoming a standard considering that there are only proposed standards.

Definitely +1 although Thunderbirds 102 new address book does not yet support these attributes (https://bugzilla.mozilla.org/show_bug.cgi?id=1777474) - But CardBook does it and If a standard will be adopted by MZLA it would be the RFC one...

+1 support asked

Awaiting this feature, vlist has been disabled in Thunderbird (https://github.com/Alinto/sogo/commit/f0719ee409dee693e7b4792bd127ccdd4b3043f1)