A code is the unique sequence of letters and numbers which is used to identify each question, question group, eForm and visit. Each question, question group, eForm and visit in a study has to have a unique code.
Codes are different from names. Codes are unique identifiers which are used to distinguish between different objects, and must follow certain strict rules. The rules for creating names are less strict.
To create codes which work correctly, you must follow these rules:
Contain 15 or fewer characters.
Only include letters, numbers and underscore characters.
Start with a letter.
Be unique. A new code must be different from every existing question, group, eForm and visit code in your study.
Contain any spaces. You can use the underscore character as a separator, like_this.
Be a reserved word of MACRO or Arezzo.
No distinction is made between uppercase and lowercase.