This is an undocumented feature of srm 1.2.8 on Mac OS X 10.9, and is erroneously documented in 1.2.11 as a behaviour activated by the OpenBSD rm-compatible option -P. However, in both the OS X and SourceForge srm implementations, the behaviour of unlinking but not overwriting multi-linked files is always active, as long as the platform reports hard links.
This undocumented feature of srm 1.2.8 on Mac OS X 10.9 is incorrectly documented as being activated by the OpenBSD rm-compatible option -P in both the OS X and SourceForge implementations. This behaviour, however, consistently unlinks files without overwriting them when hard links are detected.