Identification List (IL)—contains the following four sections: 1. Preface—Each subsection contains a preface that includes special instructions pertaining to that individual subsection. 2. Alphabetical Index—This list of National Item Names is cross-referenced to index numbers to help locate an item when the NSN is not known. 3. National Stock Number Index—This list of NSNs is arranged in numerical order and referenced to index numbers to help locate an item within a subsection. 4. List of Items index number—Some items are illustrated for clarity. Each item listed includes action codes; handling and/or storage codes, if any; NSN; and a brief description of the item.  Action Codes—Additions, deletions, or revisions of published data are identified as follows:  Index Numbers—Items are presented in alphabetical order; index numbers are assigned in ascending sequence within each pamphlet. They are used solely as a locator device and not in place of NSNs.  National Stock Number Index—NIINs are listed in numerical order.  Descriptive Data—Important distinguishing characteristics are stated in this section.  Description—Information which appears below the item name and above the box in which the index number, NSN, and data are arranged. Operational data may appear as a footnote such as “cold weather use only.” Notes—Information regarding item special storage and handling procedures are as follows:  Navy Management Data List—This list contains all items in the subsection and shows unit of issue, price, and authorized substitutions. A separate Navy Management Data List is published for each Identification List. PROCUREMENT LEARNING OBJECTIVE: Recognize the various supply levels, and recall requisition form completion and processing procedures. Procurement is the act of obtaining materials or services. Material may be procured by requisition (items with federal stock numbers) or open purchase (items without federal stock numbers, procured from nonfederal sources). Requisitions are most frequently used, but open purchase is used for procuring 13-6 N-new C indicates items not previously included in the basic publica - tion, change bulletin, or change notice; or reinstaten- ment of a previously deleted item. C-change C indicates a change in data since the previous publication. D-deletion C indicates an item that is no longer available. B C corrosive or poisonous material C C contains one or more component items of the nature described under “R” below; used in connection with assemblies only F C subject to damage by freezing G C requires refrigeration between 2E to 8EC (35E to 46EF) I C flammable or oxidizing materials M C an item containing potentially recoverable precious metals P C an item with potency period or expiration date Q C drugs or other item requiring security storage and Schedule III, IV, and V R C alcohol, alcoholic beverages, precious metals, or other substances requiring vault storage and Schedule II W C item must be kept frozen for preservation