There exists a prestigious academy with a history going back hundreds of years. Graduates are highly skilled and very much sought after for employment. For purely traditional reasons, the academy requires its students to become proficient in a skill or area of knowledge that has no use in the modern world. This could be Ancient Egyptian, an antiquated form of writing such as shorthand, knowledge of building or repairing antique steam engines, programming COBOL, etc. PCs who graduated from this academy must be sure to have this skill in their repertoire.
Dustwood is technically not a wood from a specific tree. It is an created fuel for fires.
Starting with the sawdust from a sawmill, adding a mixture of wax or pitch, and a few other things, the mixture is pounded or pressed toghether tightly. It is normally smashed into a round container, so when it is slipped out, it looks like a small perfectly round "log". (actually a lathed log, but you get the idea). It can either be used as a log or slices of a log can be used for a fire.