Administration Tool - Field Aliases Menu
Example: When the author field alias is defined for the sysauthor field, the query @author=Paul is automatically converted to @sysauthor=Paul by the field alias set.
The Coveo Platform comes with a default field alias set (see Available Field Aliases). You can create different field alias sets (see Adding a Field Alias Set), but you can only use one field alias set on an index at a time (see Modifying or Using Advanced Index Parameters). Within a field alias set, you can add, modify, or delete aliases (see Managing Field Aliases).