I know it's an old post but right, back in SAQL Server 2000, if you right clicked on an extended sproc and told it to execute, the number of parameters and their names would appear. That no longer works in 2k5 and above.
Most folks know that the second operand of xp_DirTree would limit the number of levels but most folks don't know that the third operand will return file names anytime the third operand is a non-zero value. Most of this was discovered just by trial and error.
--Jeff Moden
Change is inevitable... Change for the better is not.