1. Modern Eyeglasses - Certain death to any living history impression.

2. A Crummy Hat - Rolling the brim like a baseball cap, excess decoration, and/or wearing a cap made in the form of a shapeless feedbag. Steamed fedoras, limp unfinished hat-blanks, and anachronistic headgear will not cut the mustard.

3. A Bad Attitude - Being drilled to perfections, well-read, physically fit, and having a perfect kit is no excuse for being a prima donna, chronic whiner, stuffed shirt, or all around jackass. This includes non-period quips at inappropriate times.

4. Being Grossly Overweight - Bad for your impression and bad for your health.

5. Holding Non-functional Rank - Non-commissioned officers who cannot or will not do their jobs are just as bad as commissioned officers without troops.

6. Wearing Your Traps Around Your Knees - Sure, Jimmy Page looked cool doing this but he had a guitar.

7. Cigarettes - Try a pipe, you may like it.

8. Too Much "Neat Stuff" - Even campaigners can get the "too much stuff" disease. Keep your kit simple and lightweight.

9. The Tailored Look - For most of the war, uniforms were issued in four sizes, period. How you managed to make it fit was your problem.

10. Modern Clothing of Any Kind - Tee shirts, bandannas, sweat socks, etc. are guaranteed to ruin your impression.

11. Modern or Excessive Jewelry - Earrings and other piercings were extremely rare in the 1860s. Wristwatches were non-existent.

12. Non-Period Foods or Packaging - A "Cheez-It" box can be spotted from 100 yards in an otherwise authentic camp.