Section 3.1.2.1. The _[local]_ prefix

The string _[local]_ is reserved as a prefix to identify data names that do not appear in any public dictionary. (The left and right square brackets are included in this label.) Hence an author may construct private data names according to one of the following models, secure in the knowledge that the name will not appear in any global dictionary. With DDL1, a private data name will always have the form _[local]_private_data_name, while with DDL2 the forms _[local]_new_category_name.private_data_name and _existing_category_name.[local]_private_data_name may be used. The first DDL2 form is used for private data names in a category not already defined by a public dictionary; the second form permits the addition of local data names to an existing category. Note that the initial underscore character is dropped in the second DDL2 form.

While this convention guarantees that the new data name will not conflict with a public one, it cannot guarantee that it will not conflict with a local data name created by another author. Therefore these data names are appropriate only for testing purposes and not for release in data files that may be used by others.