The standard U.S. household wiring design has two 120 volt hot wires and a neutral which is at ground potential. The two 120 volt wires are obtained by grounding the centertap of the transformer supplying the house so that when one hot wire is swinging positive with respect to ground, the other is swinging negative.
Thus the name of a file or directory can be up to 255 characters. When specifying the full path under Windows, you need to prefix the path with \?\ to mark this path as an extended-length one (~32k characters).o be precise: NTFS itself does impose a maximum filename-length of several thousand characters (around 30'000 something). However, Windows imposes a 260 maximum length for the Path+Filename. The drive+folder takes up at least 3 characters, so you end up with 257.
The length of a SAS name depends on the element it is assigned to. Many SAS names can be 32 characters long; others have a maximum length of 8. The notable exception is user-written informats, which have a maximum length of 7. See Maximum Length of User-Supplied SAS Names. The first character must be a letter (A, B, C, . . ., Z) or underscore (_).