Owing to the spontaneous and simplistic profile of check icon, it is predominantly employed as a symbol of ‘affirmation'. International differences however may be noticed e.g. in Norway or Finland; tick is instead a symbol of No or is an error indication. In another context, the check placed in brackets implies that a previously approved fact or declaration has been revised for the purpose or extending academic researches. check mark - http://ted3derick.webnode.com/news/visitors-notice/