electron affinities in P3 method

Dear Sir/Ms,
 partial third-order propagator method (P3) as implemented in Gaussian 98
 program code and described in several papers of V. Ortiz has recently
 successfully been used for calculation of ionization potentials of molecules
 by choosing IOp(9/11=10010) modification of ROVGF keyword.
 Now, I'm interested what should that IOp mean, since in G98 IOp list there
 is no such value described and therefore I'm not sure what is the numerical
 meaning of the above procedure.
 Furthermore, has anybody tried to calculate electron affinity of a compound
 using the same method? (Or do any of the readers know of such a work?)
 If yes, what would be the relevant IOp modification for such a
 method/calculation?
 (I apologize if the question is trivial.)
 Please, respond to my e-mail.
 I thank You very much in advance,
   Vjeran Gomzi, Ph.D. Student,
   Department of Biophysics
   Faculty of Pharmacy and Biochemistry,
   Ante Kovacica 1,
   10000 Zagreb
   CROATIA
   tel. +385 1 4812128
   fax. +385 1 4856 201