A document, which may be referred to as a “citing document,” may include citations to one or more cited documents. An index of such documents may be referred to as a citation index or citator. A citation may be preceded in a citing document by introductory text, which may be called a signal, and one or more entries in a citation index may indicate which signal, if any, introduced a recorded citation. Computerized systems and methods for causing such display are also provided.