Steps
2. If the data class does not yet exist, add the data class.
3. You may edit all the properties in common for a data class.
You may not edit the Type after it has been set. You must create a new data class instead.
4. Set the QUERY to specify an Metadata Query Language (MQL) query that must be met before a data object that is being classified is associated with this data class.
You may enter the query by hand, copy it from a worksheet MQL or use the EDIT button to query by example through a worksheet-like dialog.
5. Click SAVE.
Example
Sign in as Administrator and go to MANAGE > Data Classes.
Click the Add plus sign. Click Metadata as the Type of data class and enter
o “Product Number Query” as the NAME
o “Product” in the GROUPS
o “General metadata-detected data class for product numbers” as the DESCRIPTION
Click EDIT to build a query and
enter “Product Number” in the 
Search
text box.
There are a number of false positives because the assumed condition is “Product” OR “Number” and “Number” has a huge amount of hits.
Let’s force an AND condition.
Remove “Number” from the Search
text box and press Enter. Then click ADVANCED.
Simply copy the MQL text, type “ AND “, and then paste the MQL text (again) after that.
Replace the second ‘Product’ with ‘Number’, click EXECUTE, and you should have:
text = 'Product' WITHIN ('Name', 'Physical Name') AND text = 'Number' WITHIN ('Name', 'Physical Name')
Click OK. Then SAVE.
You may invoke it manually when you wish to confirm that it has been performed.