In the Effects window, a chain is a single row, but in the script a chain is multiple rows, one per device. Thus when you insert a chain from the Effects window, a single row is being expanded out to multiple rows. This expansion only happens for chains, which you can recognize by the word “Chain” in the VDL column (See “How can I tell if an effect is a chain?”).
The number of expanded rows is equal to the “Devices” column of the chain in the effect window, regardless of what the description or VDL of the effect might seem to indicate. If the “Devices” column has the value 1, the inserted chain will have only one device even if it is called, for instance, a “Chain of 5”.
All the rows in the script reference the show’s local database of effects, called the Per-show effects, which are saved along with the show. When you insert a chain or any other effect into the show from a collection of effects, the effect definition (one row) is copied from the collection into the Per-show effects, overwriting the previous value or adding a new row if not already in the Per-show effects, by matching part number. The rows in the script representing the devices of the chain all reference the same effect definition in the Per-show effects for some of their attributes, such as “Description.” Other attributes, like “Duration” and “Devices” are calculated and automatically filled into to the script rows when the rows are created, because obviously the duration or device count of a chain would not be right for individual devices in the chain. (See “Representation of chains in the script.”)
To accommodate effects lists that are missing important fields of information like “Part Type”, Finale 3D automatically derives any missing fields from the fields that are not missing when inserting the effect. For example, the “Part Type” can be derived from the description of the effect or its VDL. It is actually this modified effect definition, with missing fields filled in, that is inserted or updated into the Per-show effects. Thus even if the effects list from which you insert an effect is missing columns, the effects will still show up in the show if you insert them. This automatic filling in applies to chains and to other effects that are not chains.