Scope note: This class comprises the textual or numeric information required to locate specific instances of E53 Place within schemes of spatial identification. Coordinates are a specific form of E44 Place Appellation, that is, a means of referring to a particular E53 Place. Coordinates are not restricted to longitude, latitude and altitude. Any regular system of reference that maps onto an E19 Physical Object can be used to generate coordinates. Examples: - "6°5'29"N 45°12'13"W" - "Black queen's bishop 4" [chess coordinate]. In First Order Logic: E47(x) ⊃ E44(x)