Lisa Lake/Getty Images

The National Football League is set to change its advertising guidelines to allow a limited number of commercials for hard liquor during games throughout the 2017 season.

On Friday, Joe Flint and Suzanne Vranica of the Wall Street Journal reported all ads for distilled spirits will need to include a "prominent social responsibility message." An NFL executive told the outlet the league is treating the policy as a "one-season test" but expects it to continue.

The NFL will allow four advertisements for hard liquor during each game, and the league's television partners can also feature two during pregame and postgame shows, according to Flint and Vranica. Meanwhile, products like birth control, energy drinks, gambling venues and marijuana in states where it's legal remain banned.

Concerns about ad revenue were raised during the middle of last season.

Jason Lynch of Adweek reported that NFL ad revenue was down 17 percent last November from the previous November. He noted the league was forced to give companies audience deficiency units (additional spots to compensate for failing to meet guaranteed impressions numbers).

Yet, despite lagging ratings and the ad drop, Kurt Badenhausen of Forbes reported in March the league still set a new record by generating $3.5 billion in ad revenue by season's end. All four of the NFL's network partners (CBS, Fox, NBC and ESPN) experienced an overall increase.

In December, NFL Commissioner Roger Goodell said the hotly contested presidential election played a key role in the league's television issues early in the season, per Bart Hubbuch of the New York Post.

"It's clear that the election had an impact," he said. "There's no question that going head-to-head with debates, you're going to get that kind of a [ratings drop]—particularly with an election that may have been more followed than any election in our history."

Liquor companies can help provide advertising depth. Flint and Vranica noted they spent about $411 million on ads in the United States in 2016.