OSLO — Norway’s ruthlessly successful Alpine ski team is preparing for next month’s Winter Olympics with a punishing training regimen of slaloms, weights and ice baths. So you would think that choosing what knitted woolly sweater to wear would be the easy bit.

Designed at a time when public interest in Viking culture is experiencing a renaissance, the theme for Norway’s Alpine ski team uniforms this season is “the Attacking Viking,” a homage to the team’s nickname. But the sweater features a symbol known as the Tyr rune, which neo-Nazis want to claim as their own.

There is little evidence that the rune originally had any symbolic significance beyond its sound value, but the letter shares the name of a Norse deity popularly understood as the god of war, Tyr. Nowadays, most runologists consider it a letter no more mysterious than the letter T.

Even so, the presence of the Tyr rune on the team’s sweater design was enough to raise alarms. Norway’s security police have warned of the rise of a small but politically extreme and potentially violent group called the Nordic Resistance Movement, which uses the Tyr rune in its branding.