clarification on what constituets single, double, and triple quotes.

doc/src/Commands_parse.rst

@@ -123,14 +123,15 @@ LAMMPS:
 .. _six:
 
 6. If you want text with spaces to be treated as a single argument, it
-   can be enclosed in either single or double or triple quotes.  A long
-   single argument enclosed in single or double quotes can span multiple
-   lines if the "&" character is used, as described above.  When the
-   lines are concatenated together (and the "&" characters and line
-   breaks removed), the text will become a single line.  If you want
-   multiple lines of an argument to retain their line breaks, the text
-   can be enclosed in triple quotes, in which case "&" characters are
-   not needed.  For example:
+   can be enclosed in either single (') or double (") or triple (""")
+   quotes.  A long single argument enclosed in single or double quotes
+   can span multiple lines if the "&" character is used, as described
+   in :ref:`1 <one>` above.  When the lines are concatenated together
+   by LAMMPS (and the "&" characters and line breaks removed), the
+   combined text will become a single line.  If you want multiple lines
+   of an argument to retain their line breaks, the text can be enclosed
+   in triple quotes, in which case "&" characters are not needed and do
+   not function as line continuation character.  For example:
 
    .. code-block:: LAMMPS
 
@@ -144,8 +145,9 @@ LAMMPS:
       System temperature = $t
       """
 
-   In each case, the single, double, or triple quotes are removed when
-   the single argument they enclose is stored internally.
+   In each of these cases, the single, double, or triple quotes are
+   removed and the enclosed text stored internally as a single
+   argument.
 
    See the :doc:`dump modify format <dump_modify>`, :doc:`print
    <print>`, :doc:`if <if>`, and :doc:`python <python>` commands for