how does Crit. Shrug off really work?

[helminthauge]

Talent Ice Core says "all direct critical hits (physical, mental, spells) against you have a 60% lower Critical Multiplier" and gives 60% Crit. Shrug off. But in the Character Sheet Crit. Shrug off actually reads as "gives a chance to ignore the bonus critical damage from any direct damage attacks (melees, spells, ranged, mind powers...)". I think these 2 mean different things, so which one is true? (I'd also like to know what source file is related to this.)
And if the info in Character Sheet is true, then what's the difference between Crit. Shrug off and Crit. Reduction aside from the fact that the later only works on melee and ranged attacks as it reads? And how do these 2 interact together?

[Cathbald]

Crit reduction : only on heavy armor, enemies that attack you have a flat -X% applied to their crit chance before they try to crit.

Crit shrug off : you have X% chance to ignore the bonus damage from a crit when someone crits you. They still get any "on crit" bonus they might have. Every single talent that say they reduce crit multiplier are actually crit shrug off.

Currently nothing reduce crit mult, it probably started with one talent not saying what it actually did and then every other talents copying this talent's code and desc :p