system of indexing in which the preferred terms allocated to a particular document are syntactically combined in one or more sequences representing the only combinations available for retrieval purposes
e.g. when using pre-coordinate indexing, a manual on bicycle repair might be assigned the indexing string made up of three preferred terms in combination:
bicycles - repairing - instruction books
This brings all aspects of repairing bicycles together in a catalogue or browsing list, and might be followed by
bicycles - repairing - tools
There would be no direct alphabetical access to this subject under repairing, instruction books, or tools. This does not mean that the individual concepts within a pre-coordinated string cannot be searched for separately, either as controlled preferred terms or as free text, but such methods are not part of the pre-coordinate indexing system. Compare post-coordinate indexing.