Delta specification

A delta specification, though difficult to characterize precisely, is one that looks like this: it defines a small set of features, incorporates normatively a large set of features for the same technology from another specification, and is intended to supersede that other specification. (Note: If a specification builds on a foundation AND extends that foundation, it may be in conflict with the TAG’s advice regarding orthogonal specifications.)

In general, W3C prefers publishing “full” or “merged” specifications instead of delta specifications for several reasons. The first is that the W3C Patent Policy applies to text in a document and does not extend to “technology developed elsewhere and merely incorporated by reference” (see section 8.2 of the W3C Patent Policy). Thus, in many cases, publishing a full specification is likely to increase patent policy coverage. (We recognize that if the same Participants produce both the original and the delta specification, the point is moot.) Readability and avoiding inconsistencies (which one often discovers when merging two texts) are two other reasons to prefer “full” specifications. Please contact the W3C Communications Team if you have questions on delta specifications.