In the USA, a high school diploma is often considered a different kind of qualification than a degree. This kind of idea is also expressed in the Academia.SE question Is it possible for a high school student with no academic qualifications to publish a research paper?, which seems to imply that a high school graduate currently enrolled in undergraduate studies at a university does not hold any academic credentials.
Is there any precedent for considering high school diplomas, similar non-US equivalents, or high school equivalency exams (e.g. the GED) as academic degrees? For example, if John Smith, a GED holder with no further education, needed to be referred to or addressed based on his academic credentials, would he be referred to as John Smith, GED or simply John Smith? Similarly, would (or could) it be proper to refer to credential holders such as "Ann Jones, Leaving Cert (Ireland)", "Hans Schmidt, Abitur", or William Robinson, NTCE, or would they simply be considered as persons lacking any academic credentials?