and USCS is published by LexisNexis (part of Reed Elsevier), which purchased the publication from the Lawyers Co-operative Publishing Co. in 1997 as a result of an antitrust settlement when the parent of Lawyers Co-operative Publishing acquired West. These annotated versions contain notes following each section of the law, which organize and summarize court decisions, law review articles, and other authorities that pertain to the code section, and may also include uncodified provisions that are part of the Public Laws. The publishers of these versions frequently issue supplements (in hard copy format as pocket parts) that contain newly enacted laws, which may not yet have appeared in an official published version of the Code, as well as updated secondary materials such as new court decisions on the subject. When an attorney is viewing an annotated code on an online service, such as Westlaw or LexisNexis, all the citations in the annotations are hyperlinked to the referenced court opinions and other documents. Organization Divisions The Code is divided into 53 titles (listed below), which deal with broad, logically organized areas of legislation. Titles may optionally be divided into subtitles, parts, subparts, chapters, and subchapters. All titles have sections (represented by a §) as their basic coherent units, and sections are numbered sequentially across the entire title without regard to the previously-mentioned divisions of titles. Sections are often divided into (from largest to smallest) subsections, paragraphs, subparagraphs, clauses, subclauses, items, and subitems. Congress, by convention, names a particular subdivision of a section according to its largest element. For example, "subsection (c)(3)(B)(iv)" is not a subsection but a clause, namely clause (iv) of subparagraph (B) of paragraph (3) of subsection (c); if the identity of the subsection and paragraph were clear from the context, one would refer to the clause as "subparagraph (B)(iv)". Not all titles use the same series of subdivisions above the section level, and they may arrange them in different order. For example, in Title 26 (the tax code), the order of subdivision runs: Title – Subtitle – Chapter – Subchapter – Part – Subpart – Section – Subsection – Paragraph – Subparagraph – Clause – Subclause – Item – Subitem. The "Section" division is the core organizational component of the Code, and the "Title" division is always the largest division of the Code. Which intermediate levels between Title and Section appear, if any, varies from Title to Title. For