In this context, the word pearl refers to an official term, i.e. pearl. If the “Educational Pearl” is amongst others hints that it is one of many. “Educational Pearl” merely the title of a series of which this publication is a part. (cf. scheme2006, list of publications) It is

possible that there is some meaning intended for the use of “pearl” to describe these documents, but it seems that the meaning would be hidden from the casual browser of any one of these publications. Maybe it has some meaning to the faculty and students at this institution.