My guess would be that it's some sort of improvement district (though I can't cypher what the "P" represents). Improvement districts are often single purpose entities that bring some infrastructure to an area (sewer is a good example, but it could be anything - water, floodway improvements, whatever). Any fee associated with an improvement district would - IMO - be shown as a special assessment.
Is it some type of a community enhancement fee? Some of the masterplanned communities here in Orange County (Ladera Ranch and the Talega area in San Clemente) have 1/4% fees due (based on sales price) when a property sells.
Also, some builders (I believe Lennar and possibly Hovnanian) have a type of residual fee due on resales of homes that they built.
"P" stands for "Planned".