1. A categorization and indexing system for construction documents, comprising: a computing device comprising a processor and memory for (1) receiving a plurality of digital pages having machine-encoded text and (2) identifying sheet name notations on the plurality of digital pages, wherein the machine-encoded text includes a plurality of notations, the notations including: (a) primary sheet name notations, (b) reference sheet name notations, (c) anchor notations, and (d) anchor reference notations, and wherein each of the plurality of digital pages includes at least one notation; a categorization module for categorizing each of the identified sheet name notations as one of a primary sheet name notation and a reference sheet name notation, wherein at least one of the plurality of digital pages includes at least one reference sheet name notation, and wherein each reference sheet name notation refers to a primary sheet name notation on another of the plurality of digital pages; a notation identification module for identifying: anchor reference notations on the plurality of digital pages, and anchor notations on the plurality of digital pages, wherein each anchor notation comprises at least one of: (i) an anchor identifier, and (ii) an anchor sheet name, wherein each anchor notation is associated with at least a section of the page on which it is identified, and wherein each anchor reference notation includes (1) a reference sheet name notation and (2) a reference to an anchor notation on the page corresponding to the primary sheet name notation referred to by the reference sheet name notation; an indexing module for generating a digitally accessible electronic index that: associates each identified primary sheet name notation with one of the plurality of digital pages, associates each reference sheet name notation with the primary sheet name notation on which it is identified, associates each anchor notation with a primary sheet name notation, and associates each anchor reference notation with the anchor notation and primary sheet notation to which it refers; and a report module for generating a report of the electronic index that includes at least one of: a report of indexed anchor reference notations that refer to an anchor notation that is not in the electronic index, a report of indexed anchor reference notations that refer to a primary sheet name notation that is not in the electronic index, and a report of reference sheet name notations that refer to a primary sheet name notation that is not in the electronic index.
2. The system of claim 1 , wherein identifying each of the primary sheet name notations, reference sheet name notations, anchor notations, and anchor reference notations comprises using one or more regular expressions.