+
+@item LISTING_HEADER
+A string to use on the header line of a listing. The default value is simply
+@code{"GAS LISTING"}.
+
+@item LISTING_WORD_SIZE
+The number of bytes to put into a word in a listing. This affects the way the
+bytes are clumped together in the listing. For example, a value of 2 might
+print @samp{1234 5678} where a value of 1 would print @samp{12 34 56 78}. The
+default value is 4.
+
+@item LISTING_LHS_WIDTH
+The number of words of data to print on the first line of a listing for a
+particular source line, where each word is @code{LISTING_WORD_SIZE} bytes. The
+default value is 1.
+
+@item LISTING_LHS_WIDTH_SECOND
+Like @code{LISTING_LHS_WIDTH}, but applying to the second and subsequent line
+of the data printed for a particular source line. The default value is 1.
+
+@item LISTING_LHS_CONT_LINES
+The maximum number of continuation lines to print in a listing for a particular
+source line. The default value is 4.
+
+@item LISTING_RHS_WIDTH
+The maximum number of characters to print from one line of the input file. The
+default value is 100.