Smart References is a cross referencing feature for Google Docs, which can be installed from the Add-ons menu inside the Docs app. A Smart Reference is a text element that contains a reference to a heading or numbered list item elsewhere in the document. When the document is changed, such as by updating a header or list item number, all the Smart References in the document can be synchronized at once so they display the new header text and list numbers. Use Smart References instead of regular text to reduce hassle and potential for mistakes when maintaining documents that are structured as numbered lists or that make frequent reference to previous sections. Good examples might be the clauses in a contract or a lengthy dissertation.