((country data (({2))} | flagicon/nt | variant = | size = | altlink = national under-(({1))} football team | altvar = football | age = under-(({1))}
))
((fbuicon|age|nation|variant|size=optional))
Produces a flag icon (only) wikilinked national under-NN (e.g. under-20, under-21, etc.) football team article.
((fbuicon|21|Netherlands))
→ ((fbuicon|20|Brazil))
→ ((fbuicon|21|ENG))
→ ((fbuicon|20|COL))
→ ((fbuicon|21|Romania|1965))
→