diff -upr less-458_orig/less.nro less-458_work/less.nro
--- less-458_orig/less.nro	2013-05-07 14:20:52.237332235 +0200
+++ less-458_work/less.nro	2013-05-07 14:22:23.142708098 +0200
@@ -1228,6 +1228,18 @@ Similarly, if the first two characters o
 the input pipe is used on standard input as well as other files.
 Again, in this case the dash is not considered to be part of 
 the input pipe command.
+.PP
+There are used following files to set up default preprocessor:
+.br
+	/etc/profile.d/less.sh
+.br
+	/etc/profile.d/less.csh
+.br
+These files set up /usr/bin/lesspipe.sh as a default filter. An user defined
+filter can be specified in ~/.lessfilter. This file should have an execute bit
+set and accept only one parameter, which represents a filename. If
+the user defined filter process the file, zero should be returned. Otherwise
+~/.lessfilter tries to handle the file.
 
 .SH "NATIONAL CHARACTER SETS"
 There are three types of characters in the input file: