The aim of DIRI = atru was to teach compound cuneiform signs, composed of two different signs and whose reading is not the sum of each individual signs.
For instance, the first line of DIRI is: 'SI.A (is to be read) DIRI (whose Akkadian meaning is) atru ("huge")'. The series covered six Tablets and was organised in four columns:
There are four manuscripts of Diri in the CAMS/GKAB corpus: they all come from Kalhu, and are very fragmentary.
Marie-Françoise Besnier
Marie-Françoise Besnier, 'The list of compound signs DIRI = atru', The Geography of Knowledge, The GKAB Project, 2019 [http://oracc.museum.upenn.edu/cams/gkab/Scribalapprenticeship/Lexicallists/PhaseII/DIRI=atru/]