Carbon nanotubes are one of the newest materials to be discovered, being barely 20 years old. They are also the most promising one, with one particular sample of multi-walled nanotube attaining a tensile strength of 63GPa, and with carbon nanotubes in general having a specific strength of up to 48000kNm/kg: effectively a direct exploitation of the covalent sp2 bonding between carbon atoms. Plastic deformation begins at about 5% strain. The nanotubes can be produced in lengths of up to 550mm, and thicknesses as small as 4.3Å; making them perfect reinforcement fibres for composites. They also have many other properties which may be useful in electronics, gas storage , etc. The present compilation focuses on the various characteristic types of defect which are found in carbon nanotubes, plus the relatively limited number of diffusion studies which have been performed. The 418 entries cover the period from 1994 to 2014.