+<a name=faq></a>
+<h2>FAQs</h2>
+
+<hr>
+<p>
+<b>I get the error <tt>java.lang.Error: multiple non-dropped elements
+ in sequence</tt>, what does this mean?</b>
+</p>
+
+<p>
+<font color=red><b>Note</b></font>: this question deals with the
+package <tt>edu.berkeley.sbp.<b>meta</b></tt>, which is not considered
+stable.
+</p>
+
+<p>
+When using the class <tt>edu.berkeley.sbp.meta.Grammar</tt>, you must
+supply an instance of <tt>Grammar.Bindings</tt>; this instance tells
+SBP how to create a parse tree for an expression using the parse trees
+of its subexpressions.
+</p>
+
+<p>
+SBP has no trouble determining what to do when parsing an expression
+that drops all of its subexpressions, or all but one -- for example:
+</p>
+
+<div class=example>
+A = B! C D! E!
+</div>
+
+<p>
+... in this example, only <tt>C</tt> is "non-dropped". In this case,
+the result of parsing <tt>A</tt> is simply the result of parsing
+<tt>C</tt>.
+</p>
+
+<p>
+However, if we were to leave more than one element un-dropped, SBP
+needs to know how to form a single tree out of the two non-dropped
+subtrees. There are two ways to do this. The simplest is to provide
+a tag -- a string which becomes the common parent of the two subtrees:
+</p>
+
+<div class=example>
+Expr = <b>Mult::</b> Expr "*" Expr
+</div>
+
+<p>
+If you are using <tt>AnnotationGrammarBindings</tt>, you can also deal
+with this situation by declaring a method/inner-class whose name
+matches the nonterminal (<tt>Expr</tt>) and has appropriate
+annotations. This is fairly advanced stuff, and the code it uses
+isn't quite as mature as the rest of the code.
+</p>
+
+
+<h2>Reporting Bugs</h2>
+
+<p>
+
+Bug reports are especially appreciated when you submit them as a test
+case (here's the
+<a href=../../../../../tests/testcase.g>grammar</a> and some
+<a href=../../../../../tests/regression.tc>examples</a>).
+
+This way we can add your bug report as part of the regression suite,
+and be sure we never release a new version in which the bug has crept
+back in!
+
+</p>
+
+<p>
+For now, please send bug reports to <a
+href=http://research.cs.berkeley.edu/project/sbp/list/>the mailing
+list</a>.
+</p>
+