Each cluster forms a directory identified by its name (like: 2287, 2516 for NGC clusters, 2391, 2602 for IC clusters or cr228, tr16 for anonymous clusters). The clusters are members of parent directories named ngc, ic, and anon depending on the catalogue source. Anon clusters should represent a two level structure author's name / cluster number, but this would have destroyed the general symetry and be a source of difficulty.
Therefore the path to the clusters NGC 2287, IC 2391 and anon tr16 are respectively:
Each cluster directory contains a working subdirectory, .T/, which is used to copy data or write temporary files.