Target's sudden firings of workers over their purchases of Stanley cups have raised the profile of an often mentioned — but often poorly understood — policy known colloquially as the 15-minute rule.

The rule is intended to ensure that customers have a reasonable and fair opportunity to buy merchandise from Target before employees purchase the items for themselves.

While some Target workers know of the rule, others told Business Insider that they were either unaware of it or simply unsure of how to avoid violating it.

In general, Target workers say the 15-minute rule is usually communicated verbally, if at all, and only occasionally presented in written form. Even a store employee handbook obtained by BI has no specific mention of the 15-minute duration in its summary of the employee purchasing policy, though it's mentioned in a separate document.

"Everybody says 15 minutes. I've heard that in multiple stores over the years, and I've told it to people, but I'd never seen it in writing," a Target employee speaking on condition of anonymity for fear of repercussions told BI. "I never thought about how I'd never seen it until I read it in your article."

BI confirmed the person's identity and employment. Target did not immediately respond to multiple requests for comment on the firings and its employee purchase policy.

The store employee handbook simply says that workers "cannot use their status to gain an unfair advantage over guests when it comes to purchasing merchandise."

The text of the rule that so many workers have been fired for breaking is found in a separate document called Team Member Purchasing Guidelines, which the employee provided to BI.

That person said the document was stored on an internal human-resources site that nonmanagerial employees generally couldn't access and that it required an intentional search to locate.

"It took some looking to find it," the employee said.

In a section on high-demand merchandise, the 15-minute duration is mentioned: "HDM moved to the sales floor (whether from the back room, the Guest Service desk, or as part of re-shop process) during store hours must remain on the shelf for enough time necessary to ensure the guest has a meaningful opportunity to purchase such items (15-minutes is sufficient) before team members are permitted to purchase such items."

The guidelines also say workers must be off the clock and remove their name badges when making purchases, and concealing or holding merchandise to purchase later is prohibited.

A section titled "consequences" says, "Team members who violate these Guidelines may be subject to disciplinary action, up to and including immediate termination."

Before January, instances of the company electing to choose the most severe option were comparatively rare but not unprecedented, Target workers told BI.

"It seems to happen in waves," the employee speaking anonymously said. "When this kind of stuff happens, it comes out of left field."

Other workers who knew of purchasing violations told BI that enforcement more often came in the form of a formal warning.

A list, also obtained from the employee, of prepared responses for managers to address various policy violations indicates a company preference for correcting employee behavior rather than firing them, including for breaking the 15-minute rule.

"It is your responsibility to know, understand and abide by the team member purchasing guidelines," the document says. "If you have any additional questions regarding purchasing merchandise, see a leader."

If you or someone you work with was fired from Target after purchasing a Stanley cup, please contact Dominick Reuter via email or text/call/Signal at 646-768-4750. Responses will be kept confidential, and Business Insider strongly recommends using a personal email and a nonwork device when reaching out.