For table, variable and field names, the following restrictions apply:
•Variable and field names must be unique; you can't use the same descriptor for a variable and a field.
•Following characters are allowed for the descriptor:
o First character: letter (of type UNICHAR_LETTER) or '_'
o Following characters: letters (of type UNICHAR_LETTER), numbers (of type UNICHAR_NUMBER) as well as '.', ':', '$' and '_'
•For hierarchies and relations '.' and ':' can be used.
The dot is the separator for the variable hierarchy. This way you can use e.g. "Person.Address.Street" and "Person.Address.City" as variable or field name. In the Designer you get a hierarchical structure, i.e. below "Person" you will find a folder "Address" with the fields "City" and "Street".
For relations see chapter Handling 1:1 Relations.
There are two possibilities to optimize the performance of List & Label, as the internal work for processing the variable definition APIs and the formula parsing is depending on these:
•If the option LL_OPTION_XLATVARNAMES is set, the invalid characters will be replaced with '_' (please implicitly note that the descriptor of two variables might become disambiguous). Without this option you have to take care of the correct variable names yourself, but the work for List & Label is decreased.
•List & Label is case sensitive if the option LL_OPTION_VARSCASESENSITIVE is set to TRUE, that also increases the performance.