-Note that if you want to get your zero-terminated C strings back including their
-.RI "termination, you must let " subject_length " include the binary zero, i.e."
-set it to
-.BI strlen( subject ") + 1."
+.RI "Note that for zero-terminated C strings, you should set " subject_length " to"
+.BI strlen( subject ) \fR,
+so that the dollar metacharacter matches at the end of the string, not after
+the string-terminating null byte. For convenience, an extra null byte is
+appended to the result so it can again be used as a string.