Sales number publications are available for sale and are divided into categories. For example:
Sales number I contains General Information (Reference)
Sales number IIA covers Business, Economics
Sales number IIC covers World Economy
Sales number V covers International Law
Sales number XVII covers International BusinessA typical sales number would be listed as E.87.XIII.4 where the E stands for English (the language of publication), 87 is the publication year, XIII is the sales category and 4 is the number within the category

If the sales number is not known and needs to be identified, check:

• United Nations Publications Catalogue *R JX 1977.82.C7 (Latest ed. at McGraw Desk)
  
• UN-I-QUE (http://lib-unique.un.org/lib/unique.nsf)
  
• Index to United Nations Documents (Readex Database in the Electronic Information Center)

To request an item falling in this period give the call number as: XFB
author: United Nations
title: Publications. Sales.
date/vol: E87.XIII.4

Beginning with 1993 each sales publication has been separately cataloged. Check CATNYP

United Nations materials on microfiche are usually either legislative or administrative in nature and are arranged by a series of letters and numbers that identify the issuing body ( a "document symbol").

Elements of the five principal United Nations organs, for example, are:
A/- General Assembly
E/- Economic and Social Council
S/- Security Council
T/- Trusteeship Council
ST/- Secretariat A typical document symbol item, for example, would be listed as A/51/1379, where A stands for General Assembly, 51 is the Session of the Assembly and 1379 is the specific document number

To find documents symbols, use indexes listed above.

To request this type of U.N. document give Readex U.N. Microfiche as the call number and list the item being request as A/51/1379.
Provide Readex Year for 1947-1980 period.
1947-1980 is filed by Readex Year (Alphanumeric system within year).
1981- is filed in a continuous alphanumeric sequence.