Is it okay to just write the company abbreviation on the company team building banner?

Whether to include the company name depends on the specific circumstances. This is because whether to include the company name depends on the specific situation. For example, if a team-building event is held within the company, the banner does not need to include the company name, because everyone knows who organized it and who participated. If the team-building activity is held in a society outside the company, the banner must carry the company name so that everyone can directly see which unit is hosting the activity, so as to expand the social influence of the company and the league organization.