The Financial Accounting Standards Board has published new guidance on how to judge whether “indefinite-lived intangible assets”—trademarks, distribution rights, and similar items without a set expiration date—should be marked down on the balance sheet as impaired.

The act of taking a write-down on such assets has long been tricky, and accounting rules had previously required financial reporting departments to test the value of the asset at least annually to compare its fair-market value with the value carried on the books. If the carrying value were greater than the fair market value, you had to write down the difference.

The latest amendments allow companies first to assess qualitative factors about the intangible asset to decide whether that test is really necessary—since, FASB reasoned, most intangible assets don't see wild fluctuations in their fair value from one reporting period to another. For every clunker like the “New Coke” brand that met a swift demise in the 1980s, many more are closer to the Instagram brand Facebook now carries on its balance sheet, likely to endure in their value for quite a while. If those qualitative factors indicate that the fair market value hasn't changed, accounting executives can skip the more formal comparison of carrying and fair-market values that previously had been mandatory.

FASB “expects that the revised guidance will reduce the cost of accounting for indefinite- lived intangible assets, especially in cases where the likelihood of impairment is low,” Chairman Leslie Seidman said in a statement.

This new guidance for intangible assets is follows the same logic as new rules adopted last year for testing impairment of goodwill, which had also been a big headache for the corporate accounting department. FASB first proposed the intangibles guidance in January.

The amendments can be found in Accounting Standards Update No. 2012-02, Intangibles—Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment. They are effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption is permitted.