June 19, 2007 3:47am CST
Some researchers recommend that observations be classified according to the features of the phenomenon or object that are reported or recorded. Typical categories include: * Saucer, toy-top, or disk-shaped "craft" without visible or audible propulsion. (day and night) * Rapidly-moving lights or lights with apparent ability to rapidly change direction" * Large triangular "craft" or triangular light pattern * Cigar-shaped "craft" with lighted windows (Meteor fireballs are sometimes reported this way, but are very different phenomena). * Other: chevrons, equilateral triangles, spheres (usually reported to be shining, glowing at night), domes, diamonds, shapeless black masses, eggs, and cylinders.