[DID YOU KNOW] that DAVdroid has advanced support for vCard4?

devvv4ever

DAVdroid is one of the very rare Android CardDAV apps which have advanced support for vCard4. This means that (if your server supports it – for instance, KolabNow and Baïkal do) you gain

native contact group support (KIND/MEMBER) without hacks
native support for various properties (BDAY, IMPP, etc.)
no more charset problems (vCard 4 is always UTF-8)

DAVdroid

automatically detects whether vCard 4 is supported by the server (fallback: vCard 3)
- detected by querying CARDDAV:supported-address-data property
uses vCard 4 for uploading and downloading contacts:
- GET with Accept: text/vcard;version=4.0
- CARDDDAV:addressbook-multiget with <address-data content-type='text/vcard' version='4.0'/>
- PUT with Content-Type: text/vcard;version=4.0

Sample vCard 4:

(red: some vCard4-specific properties)