demarcation

Dear Mr. Atwood,

Dear Woodland Middle School teachers,

I got to meet many of you last night. You seem nice enough and appear to be genuinely interested in spending your time around a bunch of 6th graders. Which is either valiant or crazy. I'm not sure which quite yet.

We are encouraged to take the alloted days of vacation provided in the terms of our employment. I support that idea but admit that I (along with many other IT professionals) prefer to define vacation as a period of time when being connected to the office is defined by me rather than an administrative clock.

The Associated Press discusses a move to change the lines of demarcation between our beloved Volunteer State and Georgia so that those Peach Staters can steal our agua.

What in the name of all that makes logical sense on this earth does this sentence mean?

For the demarcation of the fields where impulse should be as completely as possible dependent upon and correspondent with external situation, those in which reference should take prior place from those in which it may be subordinate to appetencies with advantage, is not a simple matter.