Quote Originally Posted by Geoff Withnell View Post
My understanding is that the black knife was carried concealed, but it was and is rude to carry a concealed weapon in a friend's house or other peaceful circumstance, so the sgian dhu was pulled out and worn visible.

Geoff Withnell
This is also the story as I've heard it. I've actually heard that it used to be called the sgian achlais (armpit knife) because that was where it was concealed when in public, and only became the sgian dhu when unconcealing it when entering a friend's house.

As far as whether to wear it or not - check your local laws. Here in Texas one commits Unlawful Carry of a Weapon (PC 46.02) if one carries open or concealed an "illegal knife" in a place that is not "on the person's own premises or premises under the person's control" or "inside of or directly en route to a motor vehicle that is owned by the person or under the person's control". And an illegal knife is defined in PC 46.01(6) - with the relevant parts being; with a blade over 5 1/2 inches long, designed to be thrown, or a dagger, dirk, stiletto, poinard, bowie knife, sword or spear. Also, switchblade knives are Prohibited Weapons under 46.05. So, IANAL but, if you carry a sgian dhu in Texas, make sure the blade is less than 5 1/2 inches. You might also want to make sure that the blade is only single-edged so that it can't be claimed to be a dagger or dirk.