Panton Principles for Open Data in Science

"I do have one small quibble. Following Peters Suber and Murray-Rust, I want Open licenses to be three things: explicit, conspicuous, [and] machine-readable. The Panton Principles come right out and say "explicit", and "machine-readable" is largely covered because the recommended licenses are available in machine-readable versions (though I'd have preferred to see that actual phrase in the text of the Principles). What's missing, to my mind, is "conspicuous"...."