Files with a comma separated value (*.csv) extension are in plain text. They contain characters stored in a flat, nonproprietary format and can be opened by most computer programs. Each *.csv file contains a set of tabular data, with each record delineated by a line break and each field within a record delineated by a comma. A field that contains commas as part of its content has the additional delineation of a quote mark character before and after the field's contents. When a quote mark character is part of a field's content, it is included as two consecutive ""quote mark"" characters.
Computers with Microsoft Excel installed open *.csv files in Excel by default, with the fields automatically arranged appropriately in columns. Other database programs also open *.csv files with the fields appropriately arranged.
The 26 CSV files (i.e., "NSDUHsaeExcelTab#-2009.csv") reflect the "Table #" tab in the 26 Excel files. Each contains the table title, column headings, and data.
The 26 CSV Notes files (i.e., "NSDUHsaeExcelTab#Notes-2009.csv") reflect the "Table # Notes" tab in the 26 Excel files. Each consists of a single column of records containing the table title and table notes.