--- a/wavelets/arg_fwt.m
+++ b/wavelets/arg_fwt.m
@@ -1,4 +1,5 @@
 function definput = arg_fwt(definput)
 
-definput.flags.type = {'type_null','dec', 'undec'};
+% default NULL incorporated for the absence of the flag have to be known too
+definput.flags.type = {'type_null','dec', 'undec', 'dtdwt','hddwt','full','cust'};
 definput.flags.ext=  {'ext_null','per','zpd','sym','symw','asym','asymw','ppd','sp0'};