It would be my best guess that the abbreviations would distinguish between a capias pro fine warrant (CP) and an alias warrant (AW). A capias pro fine warrant would be one issued by the judge from the bench when an individual has failed to satisfy a judgment according to its terms. An alias warrant would be one issued by the court for failing to enter an appearance on the citation at all.
A CP is a capias warrant. This means that you have already gone to court, reached an agreement or had a trial and was convicted, and have failed to make the payment. You cannot post a bond on this because you are already convicted. AW means that there is an alias warrant. This means that you received a ticket but failed to respond. A bond can be posted on this type of ticket.