password character requirements

So i tried resetting so i could access from my tablet, used the temp the admin emailed me but to reset to a new password i keeping getting told i didn't complete the required fields. And once i got told the password has to be between 7-10 characters. So i use 9 and got the first message again. Can someone make this easy..... just tell me how many characters, special characters, numbers and so forth are required.