The "merely linked" wording is my own. CDDL is very specific here, see my other comment above. It makes it very clear that it only applies to files copyrighted under CDDL or containing code taken from files copyrighted under CDDL. This makes it very different from GPL, which, according to RMS, applies also to everything linked with files copyrighted under GPL, i.e. the phenomenon often called "virality".