Property group	Property Name	Description	Misc.	Note
Data Source Priority	Data Source	Specify the main source, which serves as the basis for the combine operation in the data sources, to the top position.	Other UI	Refer to the Usage.
Selection options	Variable Matching Method	When combining data, choose whether to base for merging on Variable Name or Variable Position.		Variable Name, Variable Position
Selection options	Variables to Include	Specify Variables to Include in the results.	Required	Main Source Only, All sources
Selection options	Add data source index	A column is added for which data source comes from. Data source index is added in each row of data. The default name of the created column is "Data Source", which can be modified.	check-box