![1girl bangs black_footwear black_gloves black_legwear blonde_hair boots breast_tattoo breasts breasts_apart center_opening clothes_writing english_text full_body gloves green_eyes hand_on_hip high_heel_boots high_heels hinomoto_reiko knee_boots knee_pads large_breasts leotard looking_to_the_side mole mole_on_breast navel no_bra open_clothes rowdy_reiko rumble_roses ryu_(ryu's_former_site) scarf shoes short_hair simple_background snake solo standing tattoo unzipped white_background zipper rating:s score:8 post #32582](/cdn_image/preview/3b/5c/3b5c47950b3ce0d0eceac4f369233194.jpg)
This tag is to be used when a zipper in the image (usually on clothing, but applicable elsewhere) has been opened, a.k.a. unzipped.
If the zipper is still in the process of being opened, use unzipping instead.
The 下ろしチャック (lowered zipper) tag on pixiv is often used to refer to a type of unzipped fashion where the chest is left exposed with the nipples covered, oftentimes with the navel also shown.
Saber Bride is a character often demonstrative of this feature, such as in post #2501105.