Open the 
Service Order or Service Quote window.
Press F5 to open the Service Order List/Service Quote List window, select the relevant service order/quote and click OK. The Service Order/Service Quote window for that particular service order/service quote appears.
Click the line you want to register internal comments for and click Line, Comments, Internal to open the Internal Service Comment Sheet window.
In the Date field, enter a date if you want to have a date entered for the comment.
In the Comment field, enter the text for the comment. You can enter a maximum of 80 characters (including spaces).
If you need to enter additional text, go to the next line. You can fill in as many lines as necessary.