In some away game pictures why does Bill Russell's jersey say Boston while his teammates are wearing jerseys that say Celtics?

Bill Russell's jersey says "Boston" while his teammates wear "Celtics" due to a variation in the design or branding used in different games or seasons. This can occur in promotional or special games where teams opt for unique jerseys, or it might reflect an older style that Russell wore during his career. Additionally, it's possible that the jerseys were customized for Russell in recognition of his legacy, given his iconic status with the team.