That's the one thing that's probably pretty standard. Here's Amazon's S-1 from 1997, or over 20 years ago:
[T]he Company believes that it will incur substantial operating losses for the foreseeable future, and that the rate at which such losses will be incurred will increase significantly from current levels. Although the Company has experienced significant revenue growth in recent periods, such growth rates are not sustainable and will decrease in the future. In view of the rapidly evolving nature of the Company's business and its limited operating history, the Company believes that period-to-period comparisons of its operating results are not necessarily meaningful and should not be relied upon as an indication of future performance.
http://www.nasdaq.com/markets/ipos/filing.ashx?filingid=3847...
(edit:format)