The meaning of the directory's name:

lca, GLSEA, not used
lcb: GLSEA2
lcc, lcct, lcf, lcft: testing for GLSEA, not used
lcd: GLSEA3 data files
lcdt: GLSEA3 thumbnails
lck, lde, let, lru: not used
lct: GLSEA (512), not used
lwn: not used