A UK advertising group has called upon YouTube and Facebook to work to improve advertising measurement standards. The Institute of Practitioners in Advertising, or the IPA, released a public letter asking both companies to guarantee their fulfilment of certain measurement standards. It was requested that in order to work with these standards, both YouTube and Facebook become signatories to the Digital Trading Standards Group's UK Good Practice Principles. Currently, neither has responded to the call from the IPA. If the companies signed, it would impact the ways in which brand safety was managed, as well as standardising video audience measurement and video viewability issues. The IPA's director general Paul Bainsfair said that “as the two biggest online video suppliers, YouTube and Facebook have a responsibility to ensure the best possible standards for advertising on their platforms”.