The Reference section contains references to methods that perform operations of a global nature. They may be listed in any order. Here, as an example, is the reference section for the IP decoder:
NEXT_PROTOCOL (FromField protocol)
NEXT_PROTOCOL_SIZE (ThisLayerLength tot_length)
FRAME_AFTER_DECODING (IpReconstructFragments a)
Each statement in this section starts with one of the following keywords followed by a method invocation:
BYTE_STREAM_FRAMER
FRAME_AFTER_DECODING
FRAME_BEFORE_DECODING
NEXT_PROTOCOL
NEXT_PROTOCOL_OFFSET
NEXT_PROTOCOL_SIZE
PAYLOAD_IS_BYTE_STREAM (no method)
PREPROCESSING
POSTPROCESSING
RECOGNIZER
SUMMARY_COLUMNS (no method but special syntax to describe columns)
A decoder can only use one of each of these statements with the exception of PREPROCESSING and POSTPROCESSING. An unlimited number of PRE- and POSTPROCESSING directives may be included and, in each case, they will be performed in the order in which they appear.