Labels are applied to categories so you know what the answer options are (eg: Male/Female).
The metadata on labels may be "messy" (for example, questionnaire or HTML code contaminates the labels in an SPSS datafile or is carried over into the subvariable labels on categorical array).
In the web app
- You can change labels in the Variable Properties
Note: for the Append process, it is critical to run LABEL CATEGORIES on the new wave of data before Append, since Crunch does a match on category labels and not category id's (See Definitive Guide to Tracking).