In the following chapters, first those procedures will be examined which are used for the expression of general categories and general types of relationships and which are to be found- in a more or less embryonic or confused state-in a certain number of general library classifications, and also in special coding systems. A third portion of our report will relate, for comparative pur- poses, to similar procedures used in ‘natural’ or ‘artificial’ languages; we beg our readers to consider it simply as a prelimi- nary rough outline. The problems of symbols and notation raised by the expression of general cattegdes md ‘rel~5oiishi~s’ will be briefly dealt with at the end of this report. We should have liked to conclude this report with a sample of systematization, for discussion, of at least a certain number of general categories. But although we have drafted, for a number of years, various attempts at ‘categorization’ of this particular type,a8 we judged none of them to be sufficiently satisfactory to warrant even preliminary publication. Accordingly, the present report lacks a positive conclusion. We fear it will have raised more problems than it has been able to solve, and also often left dis- cussion in mid-air; our sole ambition is that it may serve as a frame of reference for subsequent studies, or, more modestly, that it may facilitate perhaps for other researchers, better equipped and better prepared than we were, more fruitful explorations.