Query.ShowVirtualFields

If checked (default), fields flagged as VirtualCore (i.e. virtual fields with fixed IDs from 4200 to 4230, e.g. Created by ID) are available for filter and query definitions in Aurea CRM.Web, >> Fields with Fixed IDs in the CRM.Core Administrator Guide (2nd table).

If unchecked, those fields are hidden.
Note: Regardless of this setting, the Number of records (RecCount) field (4230) is always displayed for queries of type WITH SUMMED, PLUS SUMMED and HAVING. Reference fields (Z-fields) are never available for filter and query definitions in Aurea CRM.Web. However, they can be defined as output fields in queries.

The Query.ShowVirtualFields setting also applies to the fields displayed in the ViewAllFields dialog, >> ViewAllFields.