diff --git a/doc/user-manual/fpakc_UserManual.tex b/doc/user-manual/fpakc_UserManual.tex
index b1dd6dd..a26c7d7 100644
--- a/doc/user-manual/fpakc_UserManual.tex
+++ b/doc/user-manual/fpakc_UserManual.tex
@@ -581,6 +581,12 @@ make
                     
                   \textbf{crossSection}: Character.
                     Complete path to the cross-section data for the ionization process.
+                    
+              \item \textbf{quasiNeutrality}: Maintains equal density between the species defined by the \textbf{incident} object and the others in the case by modifying the reflection coefficient and reflecting incident particles of the species.
+              The required input is:
+                
+                \textbf{incident}: Character.
+                  Name of the incident species that will be reflected.
             \end{itemize}
           \end{itemize}
         \item \textbf{EM}. Array of objects.determines the boundary conditions for the electromagnetic field.