This Official AAVSO file report format was released on January 15, 2008.
Files of observations uploaded to the AAVSO via the WebObs File Upload  tool must be formatted in the Official AAVSO Format. Visit our page on Software that exports to AAVSO format  to help format your observations.
The formats are very similar. However, the extended format includes more fields for the additional information we would like to record about photometric observations. Both formats are ASCII text based and delimited based on a character of your choice (as opposed to the original format which was column deliminated).
Information on filters accepted for the AAVSO International Database may be found here .