Here’s another dispatch from the weird world of Pennsylvania liquor law: The Pennsylvania Liquor Control Board has explicitly barred the state’s wineries from promoting volume discounts — such as 25 percent off a case of Cabernet Franc — because that amounts to an inducement.

Wineries are, on the other hand, allowed to offer a list price for a case of wine that is lower than the per bottle price, as long as they don’t promote the discount, according to an advisory opinion published last week.

The opinion, which goes against long-standing practice at many Pennsylvania wineries, was designed to establish clear authority for law enforcement officials to issue citations for volume discounting, said Matthew B. Anderson, a lawyer with Norris McLaughlin P.A., who wrote Tuesday about the opinion on his firm’s Liquor Law Blog.

“From what I understand, there wasn’t necessarily legal authority to issue citations for that and now there is,” Anderson said. “It was murky, at best."

A spokesperson for the PLCB said the latest opinion was far from the first on the topic. For example, the agency in 2012 said that a winery was not allowed to offer discounts to members of a wine clubs, another practice that continues in the state.

Anderson said wineries are allowed to do what breweries do. Breweries might charge $4 for a single 16-ounce beer, but $12 for a 4-pack of 16-ounce cans. That amounts to 25 percent discount per ounce.

Wineries can still discount a case of wine by 25 percent compared with the single-bottle price for 12 bottles, but, Anderson said, they can’t say explicitly: “I’ll give you 25 percent off if you buy 12 bottles of wine.”

Jennifer Eckinger, executive director of the Pennsylvania Winery Association, said she could not comment on the Liquor Control Board’s advisory opinion. Data downloaded Tuesday from the Liquor Control Board’s web site showed there are 393 active licensed limited wineries in the state.

Editor’s note: This article was updated at 11:59 a.m. on Aug. 7 to show that the PLCB had previously issued opinions saying that advertised discounts were not allowed.