1. A method of generating an index for a retrieval of data provided by a document, the method comprising: selecting data within the document; assigning a category to the selected data, the category being used to categorize the selected data within the index; assigning a timestamp to the selected data, the timestamp specifying a time frame after which a reminder function is to be invoked; determining a location indication of the selected data, the location indication being a path or address of the document providing the selected data; storing the selected data, the category, the timestamp, and the location indication of the selected data as an entry of the index; responsive to the time frame passing, invoking the reminder function, wherein the reminder function comprises generating and providing a reminder of the entry in the index; and wherein the reminder function performs an action on the entry of the index, the action performed on the entry by the reminder function includes automatically highlighting the entry in the index; and wherein the entry is hidden in the index such that the entry does not appear in the index during the time frame; and the reminder function comprises changing a status of the entry from hidden to non-hidden, wherein the action performed on the entry by the reminder function includes making the entry appear in the index.