The Principles for Viewability Products guidelines were originally produced in January 2014. According to the announcement, they have been updated to reflect “how the viewability issue has changed over the last 18 months”. The principles are not specific metrics, but have been designed to be compatible with viewability metrics that may be agreed by the industry in due course.

They include guidance on: the reporting on percentage of area viewable and time; reporting viewable impressions, including special cases; disclosure of what is measured and measurement and asset render requirements.

“It’s important the industry doesn’t stand still when it comes to tackling the big issues affecting online advertising,” said JICWEBS’ chairman, Richard Foan.

“This update builds on the good work implemented last year around ad viewability and is a further step in the right direction around bringing greater transparency and trust to digital advertising.”