The SQL standard's core functionality does not explicitly define a default sort order for Nulls. With the SQL:2003 extension T611, "Elementary OLAP operations", nulls can be sorted before or after all data values by using the NULLS FIRST or NULLS LAST clauses of the ORDER BY list, respectively.
The SQL standard does not specify a default order for sorting Null values. However, the SQL:2003 extension T611 allows you to sort Nulls before or after other data values using the NULLS FIRST or NULLS LAST clauses in the ORDER BY list.