USS Solstice NCC-72718 Wikia

Conservative jewelry is authorized for all personnel and shall be in good taste while in uniform. Cultural exceptions to these restrictions are generally approved when there it does not present a safety or FOD (Foreign Object Damage) hazard (e.g. Bajoran Earings).  Jewelry shall be worn within the following guidelines: 

A.  Rings.  While in uniform, only one ring per hand is authorized, plus a wedding/engagement ring set.  Rings are not authorized for wear on thumbs.

 B.  Earrings   

 One earring per ear (centered on earlobe) may be worn while in uniform.  Earrings shall be 4mm - 6mm ball, plain with shiny or brushed matte finish, screw on or with posts.  Gold for officers/CPOs, and silver for enlisted personnel.  Small single pearl earrings are authorized for wear with Dinner and Formal Dress uniforms.

C.  Body Piercing.  Not authorized while in uniform.  No articles, other than earrings for women specified above, shall be attached to or through the ear, nose, or any other body part. 

D  Necklaces/Choker.  While in uniform, only one necklace may be worn.

E.  Wristwatch/Bracelets.  While in uniform, only one of each may be worn.  Ankle bracelets are not authorized while in uniform.