What does the DSD option do in the INFILE statement?

The DSD option in the INFILE statement is specifically designed to handle data that is separated by delimiters and addresses the issue of missing data represented by consecutive delimiters. When this option is used, SAS interprets consecutive delimiters as indicating a missing value for the variable that follows them.

For instance, if you have a data file where the delimiter is a comma, and there are two consecutive commas indicating that a value is missing between two fields, the DSD option allows SAS to recognize that absence and correctly assign a missing value for that variable in the resulting dataset.

Additionally, the DSD option also modifies how SAS processes the input, allowing it to treat strings that may contain delimiters or special characters—such as quoted strings—with more flexibility. However, its primary function is directly related to handling consecutive delimiters which signify missing data, thus ensuring the integrity and usability of the data being processed.

Other options either relate to different functionalities, like initializing data steps or specifying formats, which are not the main purpose of the DSD option.