The Chicago-based Internet coupon site Groupon will amend its S-1 public offering to remove references to an accounting metric called ACSOI, officials said.Groupon has come under fire by the Securities and Exchange Commission for using ACSOI in its S-1 filing, All Things D reported.ACSOI stands for adjusted consolidated segment operating income, something critics said is non-GAAP [generally accepted accounting principles] the report said.Critics of ACSOI claim it doesn\'t include important business operating costs such as online marketing expenses to attract new customers. That makes Groupon\'s income statements inaccurate, they said.All Things D said Groupon could file the amended S-1 offering as soon as Monday.