>>red herring n. 1. A smoked herring having a reddish color. 2. Something that draws attention away from the central issue.
[From its use to distract hunting dogs from the trail.]<<
>>red herring
Something that draws attention away from the central issue, as in Talking about the new plant is a red herring to keep us from learning about downsizing plans. The herring in this expression is red and strong-smelling from being preserved by smoking. The idiom alludes to dragging a smoked herring across a trail to cover up the scent and throw off tracking dogs. [Late 1800s]<<
It is also used to refer to new stock issues, but that's not what Dew meant.
>>red herring A prospectus that is given to potential investors in a new security issue before the selling price has been set and before the issuer's registration statement has been approved for accuracy and completeness by the SEC. This document, which provides details of the issue and facts concerning the issuer, is so named because of a statement on it, printed in red, that the issue has not yet been approved by the SEC. Also called preliminary prospectus.<<