For younger children (under 10 years of age), many information is requested from parents in the so-called parent-about-child questionnaires. These information can be recognized by the information stored in the data rows of the parents and the variable name refers by a suffix to the child about whom the information is given (t for twin 1, u for twin 2, s for sibling). For example, the school attendance of twin 1 is requested from the mother, father, stepmother or stepfather and then stored with that person in the variable edu0100t. However, such parent-about-child information can also simply be alluded to the data row of the child in question. You can find an example syntax for the variable edu0100t in the download area.