The current macro language does not have a null value available. With the introduction of the statements iniwrite and iniread in version 1.5.3 a null value is needed. If we assume that the "WritePrivateProfileStringUTF8" function in the code for the macro language is to have the same properties as the "WritePrivateProfileString", then we must have a null value to pass to either to the value for a key or for the key inself. Passing a null value is the method "WritePrivateProfileString" uses to delete either the key or the entire section. See http://msdn.microsoft.com/en-us/library/ms725501(VS.85).aspx
for the description.
A string of length zero, "" or a value 0 is not a null value. A zero length string is a blank and 0 is a value. A null value equates to "unknow". See here http://msdn.microsoft.com/en-us/library/ms191504.aspx
For more information, see this http://kmeleon.sourceforge.net/forum/read.php?4,93841