The need to disclose that a person has been found guilty of a criminal offence depends on the circumstances under which the question is asked. Most forms of application for employment, for example, do not require disclosure of traffic offences of a minor nature but there is no hard and fast rule.
Unless a particular question contains within it an indication of a time limit (for example, convictions or offences found proved within ten years prior to the date of signing the form) any relevant conviction or, if necessary, court appearance should be disclosed, again depending upon the exact form of the question.
Where a court finds a person guilty of an offence but it was recorded 'without conviction' [see Sentencing Act 2017 (SA) s 24], then they can truthfully state that they do not have a conviction.