If either all or no records are selected, marks will not be used.

If one or more records are selected on the form, then SetSelectionFilter does the following:

• Copies the current key from the form source table to the destination record

• Copies the current sort order from the table to the destination record

• Copies the current filters that are set in all filter groups

• Copies the current filter group

• Marks the selected records and sets the "marked only" filter

If no record is selected on the form, then SetSelectionFilter does the following:

• Sets the current filter group to 0 on the destination record

• Adds filters on the primary key fields that point to the current record of the form

Reference