A variable label is a string that describes a variable. Variable labels may contain spaces and punctuation not allowed in variable names. See VARIABLE LABELS, for a user-level description of variable labels.
The most commonly useful functions for variable labels are those to retrieve a variable's label:
Returns var's variable label, if it has one, otherwise var's name. In either case the caller must not attempt to modify or free the returned string.
This function is useful for user output.
Returns var's variable label, if it has one, or a null pointer otherwise.
A few other variable label functions are also provided:
Sets var's variable label to a copy of label, or removes any label from var if label is a null pointer or contains only spaces. Leading and trailing spaces are removed from the variable label and its remaining content is truncated at 255 bytes.