Use the READONLY command to make a property read-only, that is, not available for modification by the user. Read‑only is generally used in three specific ways:
•for information that is being automatically tracked, such as Initial AuditId, Date and Time, and Update AuditId, Date and Time (this information is automatically entered into the system as you touch symbols or add definitions)
•for properties that are entered through another definition editor, such as the System Architect Matrix Editor
•for properties of lines, which can automatically include the “from” and “to” symbols that they connect.