>>Tomte+(OP)
> Under the Charter Act that was adopted in 1900 under the Geneva Convention (and later amended in 1905 and again in 1910)3, the American Red Cross has the exclusive right to use a red Greek cross4 on a white field, with the only exception being that any user of such an emblem prior to 1905 would continue to have the right to use the emblem. Registrations owned by Johnson & Johnson for red Greek crosses date from 1906 and claim first use dates of 1898, and thus its right to use those marks were grandfathered based on the American Red Cross Charter Act. J&J continues using similar trademarks today...
https://www.bradley.com/insights/publications/2012/04/one-cr...
In my unprofessional opinion, the red cross should go the way of "tissue", "google", "coke", etc. It's too common, hasn't been enforced. You lose the exclusive right to it.