1. The numeric portion of the Case ID is sourced from Data-UniqueID.pyLastReserverdID which is numeric up to 18 digits. Hence the maximum Case ID is PREFIX-999999999999999999
2. However, Case ID itself is saved in @baseclass.pyID which is generally a string up to 32 characters. So the Case ID will be further restricted if you use a prefix longer than 13 characters long plus 1 character for the hyphen, e.g. the following case prefix would have the following maximum: MYREALLYLONGCASEPREFIX-999999999
3. PRPC should write an error to the log if the Case ID is exhausted either due to #1 or #2 above, but will not give any warning beforehand. Hence operations must monitor and manually change the case prefix ('Application' Definition, 'Cases & data' tab) before the Case ID reaches PREFIX-999999999999999999
4. Since PRPC no longer issues IDs sequentially but in blocks of a thousand, the actual number of case IDs usable could be as few as 1/1000th the number above. This still gives a theoretical minimum of at least 999,999,999,999,999 IDs.