Couldn't be:There are three types of pseudotypes:
p-ascii - to force the parameter to 8 bit Ascii
p-unicode - to force the parameter to 16 bit Unicode (DWCS)
p-bstr - to force the parameter to BSTR format (Visual Basic)
p_ascii
p_unicode
p_bstr
or simply: ascii, unicode and bstr

The minus "-" sign confuses a lot.