For example, ChemicalBank (CHL) had a significant drop in its stock price on April 16, 1984, from 44 to 29.
The CRSP PRC item is unadjusted for splits and on this day, CRSP also shows a Distribution code (DISTCD) of 5523, which is a stock distribution flag (see page 191 of the CRSP Manual). This is similar to a common stock split. You will see that RET, which has adjustments, does not reflect the large decline because essentially the number of shares per shareholder increased and each equivalent holding only declined by -.009.
If you are charting, using the Cumulative Factor to Adjust Price (CFACPR) as a divisor will create a more realistic price series.