What must be true for a variable created in a DATA step regarding its attributes?

The stipulation that only the name and type of a variable created in a DATA step are assigned automatically is indeed accurate. When you define a variable in a DATA step, SAS automatically assigns a name to the variable based on how it's defined in the code. The type is also inferred based on the first assignment to the variable, whether it's numeric or character.

However, the length attribute can require explicit assignment, especially if a specific length is desired for character variables. By default, SAS assigns a length of 200 characters for character variables if the length is not specified, which may not be suitable for every use case. Therefore, programmers often choose to specify the length deliberately to optimize data storage and processing efficiency.

This understanding of automatic assignments is crucial for managing variable attributes effectively within SAS, as it highlights the need for awareness regarding what attributes require attention during variable creation in DATA steps.