diff --git a/fortran/trimspNL.F b/fortran/trimspNL.F
index 64b6ef9..09e2daa 100644
--- a/fortran/trimspNL.F
+++ b/fortran/trimspNL.F
@@ -181,6 +181,9 @@ C     REAL Variables
       REAL*8 K2(MAXNL),CK(MAXNL),KLM1(MAXNL)
       REAL*8 SB(MAXNL),DLI(MAXNL)
       REAL*8 UpTiefe,LowTiefe
+C     ZT - atomin numbers, MT - mass numbers (amu), CO - concentration (stoichiometry)
+C     SBE - surface binding energy, ED - displacement energy, BE - bulk binding energy
+C     COM - ??
       REAL*8 ZT(MAXNL,5),MT(MAXNL,5),CO(MAXNL,5)
      &     ,SBE(MAXNL,5),ED(MAXNL,5),BE(MAXNL,5),
      &     COM(5,MAXNL)
@@ -189,6 +192,7 @@ C     REAL Variables
      &     ,KLM(MAXNL,MAXNL5)
       REAL*8 MU1(MAXNL5),EC1(MAXNL5),A1(MAXNL5),F1(MAXNL5),KL1(MAXNL5)
      &     ,KOR1(MAXNL5) ,DI(MAXNL5),EP(MAXNL5),ZZ(MAXNL5),TM(MAXNL5)
+C     CH1,2,3,4,5 are values of A-1,2,3,4,5 of the Ziegler tables
       REAL*8 CH1(MAXNL,5),CH2(MAXNL,5),CH3(MAXNL,5)
      &     ,CH4(MAXNL,5),CH5(MAXNL,5)
       REAL*8 CHM1(MAXNL)
@@ -386,10 +390,9 @@ C     LMAX as needed for the new format.
       JMAX=5
 
       if (OldNew(innam).eq.1) then
+C     This part reads the input file (new format) 
          OPEN(UNIT=99,file=errnam,STATUS='replace')
          OPEN(UNIT=11,file=innam,STATUS='unknown',ERR=1359)
-
-C     This part reads the input file (new format) 
 C     First line: properties of projectile
          READ(11,*) Z1,M1,E0,Esig,ALPHA,ALPHASIG,EF,ESB,SHEATH,ERC
 C     Second line: simulation related parameters
@@ -429,10 +432,11 @@ C     value A-5 of the ziegler tables
             READ(11,*) CH5(I,1),CH5(I,2),CH5(I,3),CH5(I,4),CH5(I,5)
          ENDDO
       else
+C     This part reads the input file (old format, 7 layers)
+C     To be phased out soon (aim for beginning of 2023).
          OPEN(UNIT=99,file=errnam,STATUS='replace')
          OPEN(UNIT=11,file=innam,STATUS='unknown',ERR=1359)
 
-C     This part reads the input file (old format, 7 layers)
 C     First line: properties of projectile
          READ(11,*) Z1,M1,E0,Esig,ALPHA,ALPHASIG,EF,ESB,SHEATH,ERC
 C     Second line: simulation related parameters