Snis-645

I'm assuming you're referring to the SNIS-645 standard.

The SNIS-645 code has become a cultural phenomenon in Japan, with many fans and enthusiasts collecting and trading information about the code. Online communities and forums dedicated to Japanese adult films often feature discussions about SNIS-645, with users sharing knowledge and insights about the code. SNIS-645

"SNIS-645" is the catalog number for the film titled (original Japanese title: 解禁 真正生中出し). This is an iconic work because it represents a major "genre debut" (解禁), specifically a "Real Internal Ejaculation" (真正生中出し) feature. Released in April 2016, this film is considered a landmark title in the JAV genre and a key piece in understanding the career of one of the industry's most popular stars. I'm assuming you're referring to the SNIS-645 standard