symbol or group of symbols representing a simple or compound concept
Notation may be used to sort and/or locate concepts in a pre-determined systematic order, and optionally to display how concepts have been structured and grouped. A notation can provide the link between alphabetical and systematic lists in a thesaurus and between the alphabetical index and the classified sequence of a classification scheme.
e.g., partial schedule showing notation in the left-hand column:
P200
photography
P250 - - photographic equipment
P251 - - - camera accessories
P251.3 - - - - flash guns
P251.5 - - - - tripods
P253 - - - cameras and camera
components
P253.1 - - - - camera components
P253.13 - - - - - camera lenses
P253.15 - - - - - camera viewfinders
P253.2 - - - - cameras