PP-format is a record-based binary format used in a number of the BADC's datasets. It is a Met Office proprietary format so is mainly associated with Met Office products.
The BADC holds a number of software utilities available for handling PP. These including decoding, unpacking, subsetting, converting and byte-swapping. Please see the XCONV/CONVSH pages for details on the software available.
The official Met Office Unified Model Documentation Paper F3 describes the PP-format in some detail.
More information about tools and the pp-format can be found on the NCAS CMS site.