Identifiers are arbitrary names of any length given to functions, variables, symbolic constants, user-defined data types and labels. All these program elements will be referred to as objects throughout the help (don't get confused about the meaning of object in object-oriented programming).

Identifiers can contain the letters a to z and A to Z, underscore character “_”, and digits from 0 to 9. The only restriction is that the first character must be a letter or an underscore.

Case Sensitivity

Pascal is not case sensitive, so Sum, sum, and suM are equivalent identifiers.

Uniqueness and Scope

Although identifier names are arbitrary (according to the stated rules), if the same name is used for more than one identifier within the same scope then error arises. Duplicated names are illegal within same scope. For more information, refer to Scope and Visibility.

Identifier Examples

Here are some valid identifiers:

temperature_V1
Pressure
no_hit
dat2string
SUM3
_vtext

… and here are some invalid identifiers:

7temp       // NO -- cannot begin with a numeral
%higher     // NO -- cannot contain special characters
xor         // NO -- cannot match reserved word
j23.07.04   // NO -- cannot contain special characters (dot)

Want more examples and libraries? 
Find them on