By Michael Rapoport

Updated Feb. 23, 2017 12:36 p.m. ET

In these days of alternative facts, some companies are pushing alternative accounting.

The Securities and Exchange Commission is increasingly calling out companies that offer a different flavor of “non-GAAP” accounting—reporting their numbers as if they could calculate them using assumptions or practices not permitted under generally accepted accounting principles. This goes beyond the SEC’s crusade against companies using more traditional tactics like stripping out costs from their customized measures, generally making their numbers look better than under GAAP.

SEC staffers say what they call “individually tailored” accounting is a particularly worrisome variant of the non-GAAP issue. More examples have emerged in recent days, as the commission released previously confidential comment letters it sent to companies criticizing their practices.

One area highlighted by the SEC is deferred revenue—revenue received by a company before it delivers its product to a customer. Under standard GAAP rules, that revenue is recognized when the product is delivered, but some companies are adjusting their non-GAAP numbers to account for that revenue.

Computer-security company Barracuda Networks Inc. and mobile-game developer Glu Mobile Inc. were both criticized for doing that in SEC letters to the companies made public last week. When Barracuda’s deferred revenue rose by nearly $6 million in its fiscal quarter ending last August, that boosted a measure of its non-GAAP earnings. Both companies have since told the SEC they would stop the practice.

Electric-car maker Tesla Inc. had a similar issue. As reported last fall, Tesla had touted its non-GAAP revenues as if it was allowed to recognize deferred revenue from lease-type arrangements immediately—a practice that added $747 million to Tesla’s preferred measure of revenues for the first half of 2016. After the SEC questioned the move, Tesla said it would stop reporting non-GAAP revenues.

There are other examples: Brookdale Senior Living Inc., which owns senior-citizen residential communities, included in its non-GAAP metrics cash from ventures it hadn’t consolidated on its balance sheet. The company argued it was making its results comparable to real-estate investment trusts, against which it competes. But Brookdale isn’t a REIT; the SEC said the move was unacceptable, and Brookdale said it would revise how it calculates the metrics. The company, which is under pressure from activist shareholders, is negotiating to sell itself.

The SEC lets companies give out numbers that don’t follow standard accounting rules, as long as they are accompanied by and reconciled to the GAAP figures.

That is a pretty forgiving standard. Investors who need to manage risks in this world shouldn’t rely on companies that want to pretend they are in a different one.