I can confirm just about all of this because of a recent job in this space. Whatever you do, do not do two way sync with Google's CardDAV servers or you will end up with a lot of lost data.
I wonder if they should even be allowed to call it CardDAV since you'd expect it to actually adhere to the standard.
Google is large enough not to care about this though, as long as it works with their address books on Android phones it is probably good enough for them.
Note that this post seems to be from 2014 and the situation isn't much better today!
I wonder if they should even be allowed to call it CardDAV since you'd expect it to actually adhere to the standard.
Google is large enough not to care about this though, as long as it works with their address books on Android phones it is probably good enough for them.
Note that this post seems to be from 2014 and the situation isn't much better today!