In a non-legacy Yahoo Store, there are two ways to add custom fields: through Catalog Manager under "Manage my Tables" and through the Store Editor, under "Types" (the Store Editor's "Types" are essentially the same as Catalog Manager's "Tables".) Whether you add custom fields from Catalog Manager or from the Store Editor does make a difference as each has its advantages as well as disadvantages. Catalog Manager To me the main advantages of using Catalog Manager to add custom fields are: 1) You can add multiple fields quicker 2) You can later change the field's name and even type 3) You can delete the field if you no longer need it. 4) All the fields that are available in Catalog Manager are included in the data.csv file if you download your catalog. 5) All the fields that are available in Catalog Manager are also included in the catalog.xml datafeed file, which is used by the comparison shopping engines, for example. (See the Search