How do clients maintain their lists outside of SuppressionList?

Since SuppressionList stores data in a hashed format, it’s not possible to export or retrieve data from SuppressionList in a form that humans can read.

For lists where new items aren’t being continuously added i.e. allowed/restricted ZIP codes or telephone area codes, it’s a good idea to maintain a copy of the list in csv file format with one item per line to facilitate recreating or updating the list. csv files are easy to create and edit in a text editor like NotePad.