---
title: "Identifiers"
canonical: "https://docs.cuesystem.com/space/CVCHELP/509050886/Identifiers"
format: markdown
---
> Macro (toc)

---

Elements of program code, for example, constants, variables, functions, processes, and so on are identified by their identifiers. The identifiers must fulfill the conditions: 

- They must contain only letters, numbers, and the underscore character.

- They must begin with a letter.
- They are case insensitive.
- They cannot be keywords. The keyword is a word that is used as part of the language in control constructions.

#### Example 

```visualbasic
// OK, four different constants are declared 
Const MaxTemp As Byte := 30 
Const Max_Temp As Byte := 30 
Const MaxTemp1 As Byte := 30 
Const Max_Temp_1 As Byte := 30 

// error: it must contain only letters, numbers, and the underscore character 
Const Max-Temp As Byte := 30 

// error: it must begin with a letter 
Const 1MaxTemp As Byte := 30 

// error: it is case insensitive, so MAXTEMP is already declared as MaxTemp 
Const MAXTEMP As Byte := 30 

// error: it cannot be keywords, the Value is a keyword 
Const Value As Byte := 30
```

See number data types. 

#### Structured identifier 

The structured identifier must be used when a constant, a variable, a function, and a process from another module or another controller are operated. The full path to the program element must be used. A full stop separates a controller name, a module name, and an element name. 

#### Syntax 

```visualbasic
ControllerName.ModuleName.ElementName
```

#### Example* *

```visualbasic
Temp := TouchPanel1.Main.GetTemperature()
```