When an object is a child of another object, it is possible to update a parent object field from a child object field update; this feature only works on custom-to-custom, custom-to-standard, and some standard-to-standard master-detail relationships.

Only the following parent standard objects are supported in custom-to-standard master details:

• Account
• Asset
• Campaign
• Case
• Contact
• Contract
• Contract line item
• Entitlement
• Opportunity
• Order
• Question
• Quote
• Service Contract
• Solution

For standard-to-standard master-details, these are the only supported field updates:

• Case comments updating a case
• Email updating a case
• Opportunity product updating an opportunity
• Opportunity updating an account

The special standard relation field updates cannot be used in approvals, though.