Why is the CC sampling+ license incompatible with other CC licenses?

Question

Creative Commons used to publish a license called "Sampling Plus", but according to this page, it was retired/deprecated in 2011 due to inadequate demand and "Not compatible with any other CC license".

Why was this license incompatible with the other CC licenses?

According to the human-readable summary page, the license permits:

• Creative transformations for commercial and non-commercial uses
• Verbatim uses for non-commercial uses

With the condition that:

• You attribute in the manner specified by the author/licensor

At a glance, the freedoms are a mix of NC/ND and the condition is BY. Why is this incompatible with any other CC license? What specific use cases cause it to be incompatible?

Answer 1

The Sampling+ license effectively prohibits whole-work derivatives (you can't take a Sampling+ work and incorporate it intact into another work, except in very limited circumstances). This means the license is only partially compatible with the "mainstream licenses" (BY, BY-SA, BY-ND, BY-NC, BY-NC-SA, and BY-NC-ND) -- you need to be careful about how you use the Sampling+ content in the combined work.

Going the other direction:

• You can't incorporate ShareAlike-licensed content into a Sampling+ work: it introduces an impermissible license restriction to the SA work (incompatible with BY-SA and BY-NC-SA).
• You can't incorporate NonCommercial content into a Sampling+ work because the Sampling+ license permits commercial use of derivatives (incompatible with BY-NC and BY-NC-SA).
• You can't incorporate No-Derivatives content in a Sampling+ work for obvious reasons (incompatible with BY-ND and BY-NC-ND).

This leave only one possible way of freely combining a "mainstream license" work with a Sampling+ work: incorporating a CC-BY work into a Sampling+ work. Everything else is restricted or forbidden.