About automatically classifying assets via the Unified Data Classification method

Automatic data classification is a feature that analyzes and predicts the content of registered data sources based on a subset of the data itself. In other words, automatic data classification suggests a data class for columns without human input.

When you start the automatic data classification process, the process verifies the data in the column or columns against the data classification rules in the data classes, and makes classification suggestions with a confidence score. This score is an estimation based on data samples that the data classification process collects. A deviation from the exact score is possible.
You can then accept or reject the classification suggestions manually or automatically by defining classification thresholds.

Important 

To suggest a data class, automatic data classification needs enough data. Columns with very little data may not have a data class suggested.