ABB EasyLine Series Instructions For Installation Start-Up And Operation page 7

Symbols and Typefaces in the Operator's Manual
ATTENTION identifies safety information to be heeded during gas
analyzer operation, in order to avoid risks to the user.
NOTE identifies specific information on the operation of the gas analyzer
as well as on the use of this manual.
1, 2, 3, ... Identifies reference numbers in figures.
Display Identifies a display on the screen.
OK Identifies function keys.
Preface 7