diff --git a/doc/improper_class2.html b/doc/improper_class2.html
index cb7ec916855cc4ccac12bca305c417db3f8466ce..2a4e0408c3016da1172e82ca4f7373366da58e34 100644
--- a/doc/improper_class2.html
+++ b/doc/improper_class2.html
@@ -44,9 +44,9 @@ theta2, theta3 are the equilibrium positions of those angles.  Again,
 atom J (the 2nd atom in the quadruplet) is the atom of symmetry in the
 theta angles, since it is always the center atom.
 </P>
-<P>Note that defining 4 atoms to interact in this way, does not mean that
-bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
+<P>Since atom J is the atom of symmetry, normally the bonds J-I, J-K, J-L
+would exist for an improper to be defined between the 4 atoms, but
+this is not required.
 </P>
 <P>See <A HREF = "#Sun">(Sun)</A> for a description of the COMPASS class2 force field.
 </P>
diff --git a/doc/improper_class2.txt b/doc/improper_class2.txt
index ed211de0e769db1a38b3215529f51a08a84c0096..e7742046cf2e8edcc48105094fccb5593f79e79b 100644
--- a/doc/improper_class2.txt
+++ b/doc/improper_class2.txt
@@ -41,9 +41,9 @@ theta2, theta3 are the equilibrium positions of those angles.  Again,
 atom J (the 2nd atom in the quadruplet) is the atom of symmetry in the
 theta angles, since it is always the center atom.
 
-Note that defining 4 atoms to interact in this way, does not mean that
-bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
+Since atom J is the atom of symmetry, normally the bonds J-I, J-K, J-L
+would exist for an improper to be defined between the 4 atoms, but
+this is not required.
 
 See "(Sun)"_#Sun for a description of the COMPASS class2 force field.
 
diff --git a/doc/improper_cvff.html b/doc/improper_cvff.html
index 665b3969fd379fe6b0d5131181e8e73a18143dae..dedef21f2e4cf383e300a2f8e4e50d4bfb8a5a34 100644
--- a/doc/improper_cvff.html
+++ b/doc/improper_cvff.html
@@ -40,7 +40,8 @@ the other 3 atoms.
 </P>
 <P>Note that defining 4 atoms to interact in this way, does not mean that
 bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
+linear dihedral.  Normally, the bonds I-J, I-K, I-L would exist for an
+improper to be defined between the 4 atoms.
 </P>
 <P>The following coefficients must be defined for each improper type via
 the <A HREF = "improper_coeff.html">improper_coeff</A> command as in the example
diff --git a/doc/improper_cvff.txt b/doc/improper_cvff.txt
index 6e4d0673cddab9adf9de88ff71c692df63b9e510..b58dd83382c2453fa341a7b72398ad55122a5e7b 100644
--- a/doc/improper_cvff.txt
+++ b/doc/improper_cvff.txt
@@ -37,7 +37,8 @@ the other 3 atoms.
 
 Note that defining 4 atoms to interact in this way, does not mean that
 bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
+linear dihedral.  Normally, the bonds I-J, I-K, I-L would exist for an
+improper to be defined between the 4 atoms.
 
 The following coefficients must be defined for each improper type via
 the "improper_coeff"_improper_coeff.html command as in the example
diff --git a/doc/improper_harmonic.html b/doc/improper_harmonic.html
index bf4e0c06f2076d28a6c7dd13aed2acd935c20b53..5d3604c10d57dc28e5659121e2b518413394eb87 100644
--- a/doc/improper_harmonic.html
+++ b/doc/improper_harmonic.html
@@ -38,12 +38,14 @@ is with respect to the other 3 atoms.
 </P>
 <P>Note that defining 4 atoms to interact in this way, does not mean that
 bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
+linear dihedral.  Normally, the bonds I-J, I-K, I-L would exist for an
+improper to be defined between the 4 atoms.
 </P>
-<P>The following coefficients must be defined for each improper type via the
-<A HREF = "improper_coeff.html">improper_coeff</A> command as in the example above, or in
-the data file or restart files read by the <A HREF = "read_data.html">read_data</A>
-or <A HREF = "read_restart.html">read_restart</A> commands:
+<P>The following coefficients must be defined for each improper type via
+the <A HREF = "improper_coeff.html">improper_coeff</A> command as in the example
+above, or in the data file or restart files read by the
+<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
+commands:
 </P>
 <UL><LI>K (energy/radian^2)
 <LI>X0 (degrees) 
diff --git a/doc/improper_harmonic.txt b/doc/improper_harmonic.txt
index 20d98edbaeaead23fa49f76e97489c9fb429bb12..c1170edb270e4e47cf5f072b793a8b9efcc1af72 100644
--- a/doc/improper_harmonic.txt
+++ b/doc/improper_harmonic.txt
@@ -35,12 +35,14 @@ is with respect to the other 3 atoms.
 
 Note that defining 4 atoms to interact in this way, does not mean that
 bonds necessarily exist between I-J, J-K, or K-L, as they would in a
-linear dihedral.
-
-The following coefficients must be defined for each improper type via the
-"improper_coeff"_improper_coeff.html command as in the example above, or in
-the data file or restart files read by the "read_data"_read_data.html
-or "read_restart"_read_restart.html commands:
+linear dihedral.  Normally, the bonds I-J, I-K, I-L would exist for an
+improper to be defined between the 4 atoms.
+
+The following coefficients must be defined for each improper type via
+the "improper_coeff"_improper_coeff.html command as in the example
+above, or in the data file or restart files read by the
+"read_data"_read_data.html or "read_restart"_read_restart.html
+commands:
 
 K (energy/radian^2)
 X0 (degrees) :ul