The Commons Clause licence is usually combined with a pre-existing free licence in order to forbid the sale of the covered work. Its use makes the work non-free.
The Commons Clause licence adds a restriction on sale, which it does define, to software otherwise covered by a free licence. A work so covered is no longer free software, according to the FSF's definitions, so the Clause has not been entirely well-accepted by the community. That also means questions about it may not be on-topic here.
