The only way you can find out what was "invalid" is to view the source of the page. Search for this error message and you will stumble upon the following line:
Of course they expected you to do this and to know regular expressions rather well so that you could figure out that they did not want you to put a semi-colon in that field. How simple!
addendum [October 06, 2010]: Add double quotes to that list. I think Reliance should just support a tweet appender instead of the form and limit all submissions to short inarticulate bursts of alphanumeric vomit.
addendum [October 19, 2010]: add question marks to that list. At this point, I wonder if anyone really cares. Try complaining about network connectivity and be prepared to try and figure out what the correct for the phone number is. All you get as a hint is a popup telling you that the format is incorrect. If you get it right the first time, congratulations.