Constants can be character literals, string literals, integers, real numbers, or constant identifiers.
Constant identifiers are identifiers that have been associated with a constant by a constant definition or by an enumerated type definition.
Example
Here is an example of a constant definition group:
const
Space = ' ';
message = 'Hello';
first = 1;
last = 10;
DaysInYear = 365.25;
minint = -maxint;
linefeed = #10;