Sections 5.a. and 5.c. of http://www.gentoo.org/doc/en/security/security-handbook.xml?part=1&chap=5 should mention that limits can be used for generating proper backtraces and should link to: http://www.gentoo.org/proj/en/qa/backtraces.xml
...except that backtraces (a debugging tool) have nothing to do with security. I'm not saying that you can't allow users to run backtraces using limits, but that is beyond the scope of the document. It's good enough that it is mentioned in the backtraces guide; I don't see any need to mention backtraces in this particular document.
