Thanks, for the information.

Does the Dotres method also validate fare for date of return, compared to date of departure? For example, if certain fares require a maximum 30 day interval between departure and return, and one inputs the return to be 31 days after date of departure, would the above described fares (with the 30 day requirement) be "de-listed"?

Do the Sabre TVN or Galileo PVS methods validate for seasonality and advance purchase requirements only, as well? Or do they also provide extra information (such as day of travel, availability of fare classes), which the sabre fares/dotres method does not provide?

Or to put it another way, what different information with the fare listings do the 3 fare methods give (of course, only the dotres method allows input of return date, while dotres and PVS allow input for economy or business or first class fare listings).