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In Microsoft Purview, when you specify multiple keywords in a keyword dictionary or list, the default behavior is to perform an OR operation. This means that the search results will include all assets that contain at least one of the specified keywords.
Currently, Microsoft Purview DLP does not natively support the enforcement of strict AND logic within a single Sensitive Information Type (SIT) or keyword list. This limitation can pose challenges for organizations that need to detect data containing multiple specific keywords simultaneously.
Creating multiple custom SITs and combining them in a DLP policy or using regex patterns and proximity matching are effective ways to detect data containing multiple specific keywords simultaneously.
For more details, please refer the below mentioned documentation:
Create custom sensitive information types
Learn about using regular expressions (regex) in data loss prevention policies
I hope this information helps, please do let us know if you have any further queries.
Thank you.