-\*(lqnative\*(rq (decoded) format. Two things must be determined:
-the directory to store the content, and the filenames. Files are
-written in the directory given by the \*(lqnmh-storage\*(rq profile
+`native' (decoded) format. Two things must be determined:
+the directory to store the content, and the filenames.
+.PP
+By default (or if the
+.B \-auto
+switch is given),
+.B mhstore
+uses filename information, contained in the message, if available.
+(This information should be specified
+as the attribute `name=filename' in the `Content-Type' header
+for the content you are storing.)
+Only the basename of this filename is considered.
+If it begins with the character '.', '|', or '!',
+or if it contains the character '%', automatic naming won't happen for
+security reasons. (See below for the fall-back.)
+.PP
+Files are
+written in the directory given by the `nmh-storage' profile