To create a new ASN.1 schema file, select File -> New Schema from the File menu. This action opens a new ASN.1 schema in the Editor tab:.

ASN.1 definitions can then be added to the body of the schema. As keywords are recognized, they are highlighted in bold font as follows:

In this example, the SEQUENCE keyword is highlighted.

Each time a new brace-text block is opened by typing a { character, the block is auto-indented and a closing brace (}) automatically added. The number of spaces to indent and whether tabs or space characters should be used for indenting can be set in the Edit -> Configure menu under the Editor tab.

Additional schema files can be created by executing the New Schema command multiple times. Each invocation will result in a new tab being opened.

The schema files can be saved using the File Save commands. The schema files can be validated using the Tools -> Validate Schema menu item, or by pressing the Validate tool button. The schema file must be saved prior to attempting Validation.