Identifiers  | 
    
     
       
     
     		  
     
      
     
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According to CEI/IEC 1131-3: 1993 - 2.1.2 :
An identifier is a string of letters, digits, and underline characters which begin with a letter or undeline character.
Underlines are significant in identifier, for example "LADD_ER" and "LAD_DER" are interpreted as different identifiers. Multiple leading or multiple embedded underlines are not allowed.
Identifiers must not contain the space character.
LadderWORK ARM supports 15 character of uniqueness)
Examples
No.  | 
Feature description  | 
Examples  | 
1  | 
Upper case and numbers  | 
LW218 LW218T QX567 MYIDENT  | 
2  | 
Upper and lower case, numbers, embedded underlines  | 
The above example plus: MY_IDENT_15 My_Ident_15 abcd ab_cd  | 
3  | 
Upper and lower case, numbers, leading or embedded underlines  | 
The above example plus: _LEADING _12345  |