  The Linguistic Data Consortium (LDC) has developed hundreds of data corpora
for natural language processing (NLP) research. Among these are a number of
annotated treebank corpora for Arabic. Typically, these corpora consist of a
single collection of annotated documents. NLP research, however, usually
requires multiple data sets for the purposes of training models, developing
techniques, and final evaluation. Therefore it becomes necessary to divide the
corpora used into the required data sets (divisions). This document details a
set of rules that have been defined to enable consistent divisions for old and
new Arabic treebanks (ATB) and related corpora.
