Uniform code

From Memory Alpha, the free Star Trek reference

For the uniform code specific to Starfleet, please see Starfleet uniform code.

A uniform code was a regulation governing the proper manner of wearing uniforms, for example the Bajoran Militia uniform or the Starfleet uniform.

While on duty, Major Kira Nerys often wore a bracelet given to her by Tekeny Ghemor, though she admitted that doing so was not permitted by the uniform code. (DS9: "Ties of Blood and Water")

Major Kira was likely referring explicitly to a Bajoran Militia uniform code, though it is not clear from the script.