-# filename, the second 'G', 'C' or 'M' for generic/common/msw files. Flags
-# column may be empty or contain some additional info about this file (only
-# compile it in 16bit mode, don't compile it with this or that compiler, &c)
+# filename, the second a letter corresonding a directory:
+# G /src/generic
+# C /src/common
+# M /src/msw
+# U /src/unix
+# R /src/gtk
+# H /src/html
+#
+# The third column may be empty or contain some additional info about this
+# file (only compile it in 16bit mode, don't compile it with this or that
+# compiler, &c)