One of the most interesting types of (philatelic) articles are in my opinion the ones which have a personal connection. Take for instance the KSS members who used to work in Korea in the 1960s and 1970s. At that time they wrote quite a few articles on the philatelic situation on the ground, which has left as with many observations we can still read today (see the Korean Philately archive!).
Another example of an item with a personal connection is this cover. In itself it is nothing particularly special. It is a simple 1979 paquebot cover, cancelled in Busan. Besides the PAQUEBOT cachet it also has a SEA MAIL cachet, which was put on the cover because paquebot mail pays for surface mail only.