For people using appMeasurement, the updated getVisitNum plugin code is currently (Jan 2021) available here : https://experienceleague.adobe.com/docs/analytics/implementation/vars/plugins/getvisitnum.html

Hi @eham06 I'm trying to find the same info (https://experienceleaguecommunities.adobe.com/t5/adobe-analytics-questions/mcaamb-does-it-change-per-session/qaq-p/393971). Did you get a useful answer in the end?

I'm trying to find out whether the AMCV cookie can be used to identify unique sessions - specifically so we can sessions between Adobe and a 3rd party tool (we can pass the cookie ID through to it).  I know the MCAAMB part of the cookie is the encrypted Audience Manager 'blob' but I'm not clear whet...

Thanks so much @Ishan_Sinha_ That's really helpful.

Can anyone confirm what the 'MCIDTS' part of the AMCV cookie does?  Is it a counter for session number?  - I saw that it incremented by one between sessions, whilst the rest of the AMCV cookie stayed unchanged. I just can't find any documentation about it anywhere. 

Beware. Serialization applies *forever* essentially. So if you set an event, serialised to a user ID, then it will only be counted once *ever* for that User ID. It doesn't cause them to be only counted 'once per visit' as you've stated here. It would be better to use the 'Once per visit' option for ...