What is this principle called: "I' send data in my UOM and youconvert it

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

Suppose that every member in a community is required to exchange data using one unit of measure. For example, suppose length is required to be expressed as a decimal value in centimeters. Consider a system that internally deals with length measurements in meters. Suppose the system wishes to exchange the value "1/3 meter." Recall that the system is required to exchange values in decimal centimeters. However, there is no exact conversion of "1/3 meter" to centimeters. Should the system send the value 33 cm, 33.3 cm, 33.33333 cm? In the general case, the sending system has no insight into the precision required by recipients. Exchanging the wrong amount of precision could be catastrophic. There is a principle that a sender should transmit its original data (e.g., 1/3 meter); it is up to recipients to convert the data, if necessary, to the precision they require.

What's the name of the principle? I remember someone on this list talking about it long ago. Perhaps Len? Perhaps Walter Perry? (BTW, anyone know the whereabouts of Walter?)

/Roger