This part of the IEC 61508 contains the definitions and explanation of items that are used in part 1 to 7 of the standard 1.1 The definitions are grouped under general headings do that related terms can be understood within the content of each other . But it should be noted that these headings are not intended to add meaning to the definitions , and in this sense the headings should be disregarded.

• Year of Declaration: 1988
• Reference: IEC 61508-4
• Number of Pages: 51
• Code: GYS IEC 61508-4
• Version: First edition 1998
• ICS Number: 25.040.40