Non-default (or field-specific) delimiter is a delimiter specific to particular field. If all fields are separated by the same delimiter, use default field delimiter instead.
There are two ways to set up field-specific delimiter:
In Record Pane
Click Delimiter column of a field in Record pane and replace it by required character(s) from the list.
Such new character(s) will override the default field delimiter and will be used as the delimiter between the field and following field in the same row.
The non-default delimiter will also be displayed in the Delimiter row in Details pane, which was empty if default delimiter had been used.
In Details Pane
Click any column of the row of field just before the delimiter in Record pane of the Metadata Editor.
Properties of the field appear in Details pane on the right side. There is Delimiter property. If it is empty, default delimiter is used. Type desired value to Delimiter property.
New character(s) will override the default delimiter and will be used as the delimiter between the field in the same row and the field in the following row.
To change back to default delimiter just delete value of Delimiter in Details pane.
Remember that if you defined any other delimiter for the last field in any of the two ways described now, such non-default delimiter would not override the record delimiter. It would only append its value to the last field of the record and would be located between the last field and before the record delimiter.