<![CDATA[Micro-credentials are widely promoted as a mechanism for making granular competencies visible, yet it remains unclear whether the accumulated evidence actually supports competency recognition in the settings where technical skills are formed. This study is a systematic mapping review, conducted on a single database (Scopus) and reported under the PRISMA 2020 statement, that asks how the literature on micro-credentials and digital badges addresses competency recognition, and how far that literature reaches STEM domains and vocational education. Because the aim is to characterise the distribution of research rather than to pool effect sizes, the review is diagnostic rather than evaluative. Five concentric Scopus query sets were executed on 15 August 2026, yielding 221 records. After the removal of 31 duplicates and the screening of 190 records against four inclusion criteria, 138 studies published between 2014 and 2026 were retained and coded on educational sector, disciplinary domain, thematic focus, research design, and country of affiliation. The 138 studies were coded on educational sector, disciplinary domain, thematic focus, research design, and country of affiliation through a rule based lexical scheme followed by manual adjudication of vocational and borderline cases. The corpus grows sharply from 2023 onward, with 93 studies (67.4 percent) published in the final four years. STEM, engineering, and computing constitute the largest disciplinary domain with 45 studies (32.6 percent), yet only 13 studies (9.4 percent) are situated in technical and vocational education and training, and only 7 studies (5.1 percent) sit at the intersection of the two. Six thematic clusters were identified inductively and then arranged, through a best fit framework logic, onto a four layer recognition architecture that runs from competency standards through learning evidence and credential metadata to labour market value. This architecture, together with the evidence density quantified at each layer, is the principal contribution of the review. Evidence density is highly uneven across the layers, and the vocational share is thinnest precisely where credential infrastructure is discussed. Because the corpus is drawn from one database, these patterns describe the Scopus indexed literature and are read as an absence of evidence in that corpus rather than as proof that the underlying practice is absent. The review concludes that micro-credential scholarship has matured as a higher education phenomenon while leaving the vocational recognition problem largely unexamined, and it sets out a research agenda that connects credential design to national competency standards, workplace assessment, and employer trust.]]>
