Below you can find different documentations about the placeholders you can use in order to provide us with identities and properties.
1. Customer Service Tools
a) Zendesk
b) Freshdesk
c) Greyhound
d) Salesforce Lightning Email Templates
e) Salesforce Classic Email Templates
f) Dixa
2. Email System Provider
a) Emarsys
b) Episerver
d) MailChimp
e) Autopilot
f) Klaviyo
3. Shop Systems
a) Shopify
b) Shopware