When the world is moving towards globalisation and standardisation, India seems to be taking a step back. For something like clothing sizes for the Indian consumer market, singularisation makes way more sense than putting efforts into into introducing an entirely new size chart.
Source: wiktionary
Migrant in the singular is used as a noun or as a premodification of another noun, e.g., migrant worker (individualisation, singularisation), migrant labour (functionalisation) or migrant community (collectivisation, singularisation) and migrant families (collectivisation, pluralization), and such cases appear in all papers.
Source: wiktionary