"<Hidden>" VS. "Hidden Lines" - Difference?

[mr6jam]

In Revit Architecture 2009, when you go to Settings / Linestyles, why does it give you a Linestyle called "<Hidden>" but also a linestyle called "Hidden Lines" Why did they do that and what is its intended difference?

And, why is "Hidden Lines" green? I thought green lines are always supposed to be Model Lines (not Detail Lines)?

[Dimitri Harvalias]

The bracketed one is used by system families and can't be erased (or renamed if memory serves)
The color of the lines is controlled by their object properties and will be whatever you set it to. By default it happens to be green.

[eliteonecindy412982]

I have the worst time with these tool at times.. I put the lines down .. zoom in and zoom out and they disappear.. Or I try to draw and there is nothing but if I invert the lines.. it might show up... why?? is the tide high today?? ggr! Very frustrating at times that you can't even depend on what your looking at on screen to be correct when printed. I wish Autodesk would clean this stuff up.. it's cramping my style.