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There are 5 different fields.

sortindex

Maps to the table item_combo_value and column sortindex.

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Only works if a meta data field's data type is a combo. If in doubt, whether a meta data field is a combo data type, find out or do not use this field.

item_metafield_label_label

The language versioned label associated with a meta data field.

ItemReferenceTitle

If a meta data field is associated with an item, this field will map to that item's title.

ItemReferenceBaseID

If a meta data field is associated with an item, this field will map to that item's base ID (primary key).

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