Some user attributes (custom fields) are reserved by system because their value is automatically updated when certain events occur.
| Attribute | Description | 
|---|---|
| emUnsubDate | Last email unsubscribe date | 
| numberOfPurchases | Total number of purchases | 
| createdOn | User creation date | 
| isCustomer | Is customer | 
| lastPurchaseDate | Date of the last purchase | 
| isSpam | Flagged as spam? | 
| isHardBounced | Flagged as hard bounced | 
| isSubscribed | Is subscribed to newsletter | 
| isSubscribedAlerts | Is subscribed to transactional emails | 
| totalPurchasesValue | Total value of purchases | 
| source | Acquisition source | 
| lastEmailClickDate | Date of last clicked email | 
| lastPurchaseValue | Total value of last purchase | 
| lastEmailOpenDate | Date of last opened email | 
| lastVisitDate | Date of last visit to the site | 
| score | Score value | 
| emSubDate | First email subscribe date | 
Starting January 2025 we have some more dynamic attributes, with a special treatment.
| Attribute | Description | 
|---|---|
| activity1 | Is being set by addtocart events with the timestamp of the event. It is cleared by confirmation events (set to null) | 
| activity2 | to be added. | 
| activity3 | to be added. |