Google Tag Manager is a free tool provided by Google that allows marketers to add and update their website tags on their site hassle-free, including the Google+ rel=publisher tag.
The tag attribute rel="autor" is not relevant for Google anymore, the preferred way to specify the authorship is through the proper schema.org snippet. Authorship in web-search. Authorship markup is no longer supported in web search. To learn about what markup you can use to improve search results, visit rich snippets.
The Google Publisher Tag (GPT) is an advertisement tagging library for DFP that may dynamically build ad requests. GPT takes key details like ad unit name, ad size, and custom targeting, builds the request, and displays the ad on websites.
The Google Publisher Tag (GPT) is an ad tagging library for DFP that can dynamically build ad requests. GPT takes key details such as ad unit name, ad size, and custom targeting, builds the request, and displays the ad on web pages.