Module:Is infobox in lead/doc

Module:Is infobox in lead checks if a given infobox is in the lead, is also the only infobox in the lead, and that there aren't two of that same infobox in the article. If that is the case, it returns, and if not returns nothing.

Usage
It does not detect redirects which do not match the parameter. Redirects can be handled with an extra invocation per redirect pattern, e.g.:

Redirects can be found with [ WhatLinksHere].