Table 3 is presented only for the information of users familiar with 

 the Patent Office classification system. The table does not include all 

 of the classifications assigned to patents in the collection, just those 

 classes examined most closely. The subclasses searched were too numerous 

 to list. Patent attorneys and examiners using the bibliography for pat- 

 ent searches must realize that the criteria for patent selection were 

 primarily functional, cutting across the Patent Office's classification 

 system, so that the bibliography cannot be used to find all of the pat- 

 ents referenced to a particular classification code. 



V. INDEXING THE COLLECTION 



1. The Keywords . 



Since the Patent Office classification system could not be used to 

 catalog the CERC collection, a system of keywording was developed as the 

 basis for an index. The assignment of a keyword to each of the numerous 

 detailed categories of inventions in the collection was impractical, 

 consequently, as the following guide to the keyword system demonstrates, 

 a keyword may cover several categories, including some unobvious ones. 

 The following are not definitions of terms in the strictest sense but 

 rather explanations of the topics included under each keyword, and taken 

 as a whole, a list of all of the collection's topics. 



ARTIFICIAL SEAV/EED - Strands of synthetic material placed underwater in 

 clumps or blankets to control scour. 



ASPHALT - Bituminous material used as a binder or coating. 



BAR PROTECTION - Formation or preservation of a bar or reef. 



BATHYTHERMOGRAPH - A device for measuring the change of water temperature 

 with depth, including air temperature just above the water surface. 



BREAKWATER, CONCRETE - A concrete structure protecting a shore area, 

 harbor, anchorage, or basin from waves, including large caissons 

 and small low-co$t units. 



BREAKWATER, FLOATING - Moored buoyant units for protecting harbors and 

 shore areas from wave attack . 



BREAKWATER, PNEUIIATIC - A bubble curtain for wave dissipation. 



BREAKWATER, RUBBLE - A moiond of soil or random-shaped and random-placed 

 stones protected with a cover layer of selected stones or specially 

 shaped concrete armor units, including structure cross sections 

 useful as groins or jetties if the function was not specified in the 

 patent. 



BREAKIVATER, STEEL FRAME - A wave-dissipating steel maze or a solid bar- 

 rier of sunken ship sections or of steel caissons. 



17 



