documented backward-compatible change to parsing of NMEA sentence

java/net.sf.marineapi/src/net/sf/marineapi/nmea/sentence/SentenceValidator.java

@@ -38,7 +38,9 @@ public final class SentenceValidator {
      * <ul>
      * <li>Starts with '$' character
      * <li>'$' is followed by 5 upper-case chars and a comma (sentence type id)
-     * <li>Length is max. 80 chars long (excluding &lt;CR&gt;&lt;LF&gt;)
+     * <li>Length is max. 205 chars long (excluding &lt;CR&gt;&lt;LF&gt;). This is a deviation from the NMEA spec,
+     * which allows only for 80 characters, which is not sufficient for long decimal values. Allowing for
+     * more characters is backward-compatible.
      * <li>String contains only printable ASCII characters
      * <li>Checksum is correct and separated by '*' char (unless omitted)
      * </ul>