Although a good data-format can only be an Open Standard, FSFE's Bernhard Reiter argues that this requirement alone is not enough. Originally written for last year's Document Freedom Day in German, the article "The minimal principle: because being an open standard is not enough" is now available in English. In a nutshell Bernhard argues that the data-format needs to solve a problem adequately: It should be a good fit from a functional point of view, as well as on a technical level. In order to judge this, there are a number of things to consider: efficiency, maintainability, accessibility, extensibility, learnability, simplicity, longevity and a few more. Two central questions here are: How well does the data-format solve the problem and --more interesting-- is there a simpler format that could solve the problem just as well?
This does not mean that every time you stumble over an existing standards, you should develop your own, even smaller one.
By XKCD under CC-By-NC 4.0