The so-called weak-beam (WB) technique has been widely employed to elucidate dislocation near-core properties. To a very large extent WB images reflect the intimate structure of lattice defects through signals that may, however, be significantly convoluted. This contribution reviews selected situations where various factors affecting images must be taken into account. A less-common method to investigate crystal order under WB is also reported. (c) 2006 Springer Science + Business Media, Inc.