What do the difficulties mean?

When selecting a server, I see Veteran, Regular, and Recruit. Do these designations have any in game effects or are they more like reflections of the general attitude of the server?

Solution 1:

According to the DayZ Wiki:

Servers differ in difficulty level, regular difficulty allows third-person, has a crosshair, and allows you to see other players nameplates. Veteran servers do not permit these.

Additionally, I found this forum post which relates to the proximity detection of zombies according to the difficulty level:

• Recruit Difficulty - Zombies will be highlighted regardless of their location. (shown as white dots around the edges of your screen or through walls)
• Regular Difficulty - Zombies will be highlighted only around the edges of your screen (again shown as white dots)
• Veteran Difficulty - There will be no highlighting of zombies anywhere on your screen.

As far as I can tell, the proximity detection is the only difference between Recruit and Regular, while the lack of third-person and cross-hair support is the main difference in Veteran.

It is worth noting, however, that your mileage may vary depending on the server, as any of these options (third-person/crosshairs, etc.) can be disabled at any time by the server admins, allegedly.