The outer tag is the name of the GSCP: scp_getauthorandbooks. The next level of tags represents the names of the declared 4GL parameters. For parameters that represent user classes, the attribute names of the user class are themselves tags nested within the user class tags.

Array parameters look the same as a single user class parameter, except that they repeat for each row in the array. In the preceding example, the parameter b_arr_UCBooks is an array of books with two elements. There are two sets of tags named b_arr_UCBooks at the same level. The attribute arr_UCEdition is an array attribute of the uc_book class, and in the first book, there is only one edition. In the second book element, two editions are available.