Extinction and standardization corrections to infrared measurements are of the utmost importance in astronomy. Various views on these concepts and problems of implementation in infrared photometry are discussed thoroughly and recommendations are presented. Among these are: the adoption of narrower broad-band "Johnson" filters that are better centered in the atmospheric water windows than is currently the case; the measurements of atmospheric water vapor content concurrent with the astronomical measurements; the use of appropriate atmospheric models to treat the extinction adequately; and the publication of complete details of the systemic passbands and their transformability to other systems. To conclude the volume, R. Bell summarizes and comments on the contributions to the symposium, and the editor adds a concluding postscript on post-meeting developments and perspectives.