A system and method for facilitating annotation of a document co-browsed by multiple attendees of a collaboration session. A co-browsed page is served to the attendees by a collaboration server. An attendee (e.g., the host) annotates the page by highlighting a portion, placing or moving a pointer, scrolling the page within a window, or taking some other action. A collaboration applet operating in conjunction with the attendee's browser notes the position of the annotation (and size of annotation if it involves highlighting) and normalizes that position relative to the page. The collaboration applet then transmits an annotation event to the collaboration server, with the normalized position. The event is forwarded to other attendees, where the annotation is recreated.