A while back I tinkered was tinkering with some concepts for blood type and allergy tabs often seen on military combat uniforms. One concept I has was a hexagonal modular concept, where each component was its own patch that aligned with others.
Here’s a conceptualization of the idea with rank, rate (navy job), blood type, and allergy tabs. Not sure ‘tab’ is entirely correct, but it works for the moment? Maybe a ‘puck’ would be better. Colors for this one come from the US Navy’s Type 3 working uniform.