The <tt/score/ commands adds <em/value/ to a message's score if <em/pattern/
matches it. <em/pattern/ is a string in the format described in the <ref
-id="patterns" name="patterns"> section. <em/value/ is a positive or
-negative integer. A message's final score is the sum total of all matching
-<tt/score/ entries. However, you may optionally prefix <em/value/ with an
-equal sign (=) to cause evaluation to stop at a particular entry if there is
+id="patterns" name="patterns"> section (note: For efficiency reasons, patterns
+which scan information not available in the index, such as <tt>˜b</tt>,
+<tt>˜B</tt> or <tt>˜h</tt>, may not be used). <em/value/ is a
+positive or negative integer. A message's final score is the sum total of all
+matching <tt/score/ entries. However, you may optionally prefix <em/value/ with
+an equal sign (=) to cause evaluation to stop at a particular entry if there is
a match. Negative final scores are rounded up to 0.
The <tt/unscore/ command removes score entries from the list. You <bf/must/