Continuing Resources

This section addresses the classification of continuing resources, which include serials and integrating resources; rules for special types of material may also apply. When classifying continuing resources, particularly serials and series, see also Monographic Series, Cutter Numbers, and Congressional and Legislative Branch Publications chapters as relevant.

Identifying a Continuing Resource

Continuing resources are publications that are issued with no predetermined ending; they commonly carry numbering, dates, or both and are intended to be published indefinitely. Types of continuing resources addressed herein are serials, integrating resources, and series.

Base classification decisions on information that can be discerned from the publication and obtained from the issuing office. The agency’s expressed intent for the publication should be considered as a determining factor in establishing a class for a new continuing resource. For some publications, especially series, an issuing agency may specify that it intends to publish additional volumes. Keep in mind that a publication may cease after a relatively short period of time and without advance notice due to agency changes in priority, changes in administration, or other factors.

While individual volumes of a series always have both a common title and an individual title, individual volumes of a serial occasionally bear a theme title in addition to the serial title. If titles present on volumes are ambiguous, then it may be necessary to contact the issuing agency to determine if a particular publication is either a serial or part of a series.


A serial is a continuing resource which is issued in successive parts, has a consistent title, and has some means of uniquely identifying individual issues, such as volume number, issue number, or coverage date. Serials may have an occasional issue which has an additional distinctive title, but in general will have the same title from issue to issue (with minor variations possible).

The frequency of issuance may be weekly, monthly, annually, or other time period. Some serials may be issued irregularly.

LC 1.18: Library of Congress Magazine (bimonthly)

In most cases, a serial title is represented in the SuDocs classification system by a unique class that identifies the serial title. Serials may have titles that include the words annual report, progress report, or accomplishments for, followed by dates or designations such as fiscal year. Look for wording that indicates that the title will be published with regular frequency.

If a publication has apparent qualities of a serial, but the title does not clearly convey seriality, then review the preliminary pages, introduction, or other prefatory or explanatory background to see if the publication is intended to be issued on a regular basis.

Integrating Resources

Integrating resources have updates that are integrated into the resource as a whole and do not remain as discrete parts. Each instance of an integrating resource, either as it is first published, released, or subsequently updated, is referred to as an iteration. Publishers sometimes identify iterations with designations such as version, edition, update [number], or other term.

HS 4.106/2:2015 Regulations of U.S. Customs and Border Protection
(2015 edition)
Subsequent iterations of revised pages of the previous 2015 edition:  
HS 4.106/2:2015/REV.PGS.1 
HS 4.106/2:2015/REV.PGS.2

The most common type of integrating resource in Federal depository libraries traditionally has been the loose-leaf binder. As updated pages were received by libraries, they would be integrated (interfiled) into the base volume. Increasingly, the tangible format for many resources has been replaced by such non-static digital resources as databases and websites.

Assigning New Continuing Resource Classes

As a general rule, continuing resources will be assigned a new unique class if no existing class number is available. If the publication being classified is unrelated to the publications in classes already established, find the highest number at the end of the issuing agency’s classes and assign the next available number. Occasionally, classes will be so closely grouped together that there is no number available for the new series or serial title. Additional classes may be assigned using a dash-number to solve this problem.

The base classification number for a continuing resource (before issue designation is added in the suffix) ends with a colon (:) or a slash (/), which signifies its ongoing nature:

GP 3.8/8-9: Catalog of U.S. government publications
(Non-static database)
GP 3.36/2: Federal depository library directory
(Continuously updated website)
HH 14.2:D 64/ Diversity works
I 29.173: Climate Change Response Program news
Y 3.D 37/3:1/ Year in review (Delta Regional Authority)

Works Related to Category Classes

Works that are related to one of the established Category Classes may be attached to that class by use of a slash and numbers. For example, if the work consists of manuals, the new class can be attached to the .8 category class: Handbooks, manuals, and guides:

National Energy Technology Laboratory (NETL) 
E 12.8: Handbooks, Manuals, Guides category class
E 12.8/2: Publication standards manual (NETL)

Works Related to Existing Classes by Subject

Subject-related serials and series are attached to established classes by use of a slash and numbers. A new work may be related to other publications by its subject matter, or it might only share the same subordinate office or agency as issuing body. When assigning a new class for a serial or integrating resource, see if the new publication is related by subject to previously established classes.

Group works by subject using dash numbers after slash numbers. If a dash-number can be assigned which enables similar publications to be collocated in the classification system, use this method rather than using the next available class number. This treatment helps to keep the new serial or integrating resource in proximity to subject-related classes.

All of these E 3.11/5 classes cover serials related to the subject of petroleum.

All of these A 93.73/2 classes cover serials related to rural conditions.

The dash-number should be used only after a slash number even if this means that a new series is not always classified in proximity to related classes. Giving the new title a new slash-number may be unavoidable.

New Classes to Reflect Changes for Existing Serials

New class numbers for previously classified serials should be established when:

  • Two or more serials merge to form a new publication, or one serial splits to form two or more new publications.
  • The issuing agency, as reflected in the class stem, changes.

If the title of a serial changes, then the class number remains the same unless one of the two exceptions listed above applies.

Serials within Series: Separate Class Approach

Certain agencies publish numbered series which include serial works. Although it is possible for the same series number to be assigned to every issue of the serial (see next section), it is more common for each issue of the serial to bear a unique series number.

When serial issues have designations distinct from the main series numbering, then a separate class should be established for a serial within a series. If possible, attach the new class to the existing numbered series class by using a dash or a slash; otherwise use the next available number.

C 55.13/2: NOAA Technical Memorandums: NMFS (series)
C 55.13/2-4: Fur seal investigations

In the example above, the series number will not be used after the colon of the new class for issue designation; dates associated with serial issues will be used instead. Congressional reports, documents and committee prints that use the Senate numbering system are exceptions to the rule; see Congressional and Legislative Branch Publications for more information.

Serials with a Constant Series Number

When a serial belonging to a numbered series is uniquely identified by a series number that remains constant across issues, a new class does not need to be established. Use the constant series number in the suffix (after the colon) of the classification number.

A 1.76: Agriculture Handbooks (series)
A 1.76:305/ Directory, professional workers in state agricultural experiment stations…
(Agriculture handbook; no. 305)
 A 1.76:305/987  
(1987 annual issue) 
A 1.76:305/990  
(1990 annual issue) 

Each annual issue of the Directory appears as no. 305 in the Agriculture handbook series.

Cuttering a Serial
When Not to Establish a New Class Stem for a Serial

Serials within Series: Cuttering Approach

When a serial resides within a series, the individual issues of the serial often are scattered and sometimes lack designations. In these cases, an alternative to creating a new stem is to attach a Cutter number to the series stem. This identifies the serial and collocates its issues.

I 19.4/2:/ U.S. Geological Circular (series)   
(SuDocs class assigned to the series)       
I 19.4/2:EN 2/ U.S. Geological Survey energy and wildlife research annual report for …
(SuDocs class assigned to the serial within the series)
I 19.4/2:EN 2/2017 U.S. Geological Survey energy and wildlife research annual report for 2017
(SuDocs class assigned to the 2017 volume for the serial, which is also U.S. Geological Survey circular 1435)

Another example of this practice is found in the Foreign Labor Trends series (ceased in 2006). Each title in the series was a serial, and most titles were issued annually. There were over fifty serial titles in the series, each representing a particular country or jurisdiction. An individual class could have been established for each serial title. However, the decision was made to use the series class stem, L 29.16: and the Cutter number for each geographic area to identify each title.

If feasible, consider the anticipated number of serial titles in a series before determining whether a unique class should be established for each title. If many new classes would result, Cuttering is recommended because it results in fewer classes and retains the publications in close SuDocs proximity.

Publications of Short Duration

Publications of short duration are planned by the issuing agency to be published only for a short time, which can range from a few days to five years. They may be associated with a time-specific event such as a national celebration, centennial, bicentennial, long-running exhibition, special project, convention, conference, or short-term funded research project. They cease publication when the event is over (or soon thereafter).

New class stems should not be established for publications of short duration. Class these items in an appropriate category or publication type class. Follow with a Cutter number and end with a slash.

I 53.59:G 76/2/ Livestock grazing plan amendment – EIS (Grand Staircase-Escalante National Monument)
(A newsletter intended only to be published during the scoping period for a proposed amendment to an Environmental Impact Statement (EIS); Cuttered under G 76 for Grand Staircase)

Other cases for Cuttering

Classifying a serial by adding a Cutter number to an existing class stem may also be the preferred treatment in these cases:

  • Serials that have ceased by the time that cataloging occurs
  • Monographs that are issued in revised editions frequently enough to merit serial treatment for convenience

Note: Continuing resources classed by Cuttering do not appear in the List of Classes.

For related guidance, see:

Bibliographic Cataloging: Continuing Resources: Serials: Classification of Ceased Serials Being Cataloged for the First Time by GPO

Cataloging Guidelines: Bibliographic Cataloging: Continuing Resources: Serials: 086 - SuDoc Number

Serials Designation

In SuDocs construction for serials, generally use a designation in the position that follows the colon to uniquely identify the publication. For serials, designation consists of volume and, if present, issue number and/or date.

If a publication has consecutive numbering which continues from year to year, then the numbering alone is sufficient.

A 13.66/16:24
Science update (Pacific Northwest Research Station)
(Issue 24, Fall 2017) 

Number 1 for First Month Appears Annually

For some serial titles, the first issue of the year always begins with number 1. Rather than add the date after the number, the date is used first to keep the year’s publications together.

D 5.315:2004/1
Notice to Mariners
(No. 1, January 3, 2004)

If the date were not used before the issue number, identically numbered issues for different years would be filed next to each other and not be in useful order.

Date incorporated in Series Number

For many serial titles, agencies will often incorporate the date of the publication in the series number that is assigned to the publication. In that case, treat the publication as a numbered series and use the date as it is incorporated in the series numbering system and as it appears on the publication.

Exception: Sometimes the agency will place the year designation after the issue number, for example, 1-2016. In these cases, ignore the agency designation and use the four-digit date format, a slash, and the issue number: 2016/1.

Volume and Number

When a serial issue is identified by a volume number and issue or part number, represent the designation by volume number, a slash, and the issue or part number. Do not include abbreviations for part, volume, or number within the suffix for a serial issue.

C 55.313:114/4 Fishery Bulletin
(October 2016, designated Vol. 114, no. 4)


Annual (and Less Frequent) Publications  

For annual and less frequent publications, use the four-digit year date after the colon.

For reports of publications covering more than one year, use a four-digit year format for elements of the date range separated by an intervening dash, such as 2014-2015.

Y 10.13:2017-2027 The budget and economic outlook (Congressional Budget Office)

Semiannual Publications

Semiannual publications are treated in much the same way as annuals. The first publication uses the four-digit year format for the date. The publication for the second half of the year uses the same date followed by a dash and the number 2 (-2). Do not use a dash and 1 (-1) on the first issue of a semiannual publication.

FHF 1.1/4:2013-2 Semiannual report to the Congress 
(Federal Housing Finance Agency, Office of Inspector General)

Publications Issued Three or More Times a Year

Quarterly, monthly, weekly, etc., publications are classified with a four-digit year format for the date, a slash, and a number or another indicator, such as a season. If a publication has issues that are only designated by the name of the month, then use numbers for the months of the year (January=1, February=2, etc.).

If the publication is issued quarterly there is usually a designation for a season or a numeric designation (number 1, number 2, etc.). If the issue has a numeric designation, prefer to use that number after the slash instead of using a number representing the month.

LC 1.18:2017/6 Library of Congress Magazine: LCM
(November/December issue, designated no. 6)
I 3:70:2016/FALL My public lands: the Bureau of Land Management magazine
(Fall issue)
AE 2.106/2:2016/4 Code of federal regulations. LSA, list of CFR sections affected.
(April 2016 issue)

Variations in Publication Cycles

If two issues are combined within the same year, use the date, a slash, and both numbers separated by a dash, for example, 2017/3-4.

If two issues for two different years are combined, use four-digit year dates, slashes for the issue, and separate each by a dash, for example, 2015/6-2016/1.

If a typically regularly-issued publication has a gap or gaps between volumes, nevertheless retain standard designation when publication resumes. For example, if a publication is a monthly, but not issued in August, then designate the September issue as number 9.

Release Date vs. Coverage Date

Some serial publications carry either a release or publication date as well as a coverage date. While the coverage date reflects the coverage of internal content such as data within a reporting period, the release date reflects the publication date. An annual report may carry only a release date on the title page, but further examination indicates that the annual report volume covers the prior year.

A decision on which date to use in the classification number should be made when establishing the class and should be followed consistently thereafter. For example, on a monthly publication, the statistics may cover January 2016, but the more visible date is a February 2016 release date. Do not decide immediately that the class should be 2016/2 for the February issue. Prefer the coverage date: 2016/1.

Look closely at classes assigned to earlier issues to determine which date is being used for classification purposes. Special caution is necessary at the beginning of either a new calendar or fiscal year.

In general, prefer to use the coverage date of a publication rather than the release date. If the coverage date is not readily discernible, however, use the release date. This decision should be made when the class is first established, then followed consistently throughout the class.

Special Issues of Serials

Special issues of a serial should be studied carefully for content and publication patterns. If they are issued on a regular basis and bear distinctive titles, they should be given a separate class and cataloged separately.

Special issues published irregularly or on a one-time basis are assigned the same classification stem as the parent publication. Add /SPECIAL ISSUE or a similar designation, e.g., /SPECIAL EDITION or /PRELIM. ISSUE to the end.


If a supplement to a serial publication is issued and it lacks a distinctive title, it should be classed with the serial title. A slash and the standard abbreviation for supplement, /SUPP., are added to the end of the classification number of the publication being supplemented. For guidance on suffix words, see also Additions to Book Numbers.


 An index should be given the same classification number as the publication it indexes, followed by /INDEX. In the past, some indexes were given separate classification numbers. In the latter case, retain that separate class for revised editions.

If there is only one index per year, add the year, a slash, and /INDEX at the end of the class:

[SuDocs stem]:2016/INDEX

If there is more than one index, then indicate which months are covered:

[SuDocs stem]:2016/1-6/INDEX
(Semiannual index, January-June)
[SuDocs stem]:2016/1-12/INDEX
(Annual index, if cumulative)


Use the numbers which are assigned to the index, followed by /INDEX.

AE 2.106:83/1-40/INDEX Federal Register
(Index, Vol. 83, Nos. 1-40)

If the index covers a complete volume, add the volume number, a slash and /INDEX at the end of the class.

[SuDocs stem]:4/INDEX
(Index to volume 4)

If the index covers parts of volumes, include numbers as follows:

[SuDocs stem]:4/1-6/INDEX
(First semiannual index, not cumulative)
[SuDocs stem]:4/7-12/INDEX
(Second semiannual index, not cumulative)
[SuDocs stem]:4/1-12/INDEX
(Final cumulative index)

Frequently Revised Monographs Cataloged as Serials

Sometimes a work originally intended for one-time publication may be frequently reissued in revised editions. In this case, GPO will catalog the monographs on a single serial workform for convenience. A new class is established beginning with the first revised edition. GPO defines “frequently revised” as every five years or more frequently.

When a new class number is assigned in this scenario, GPO’s general policy is not to retrospectively reclassify the titles previously treated as monographs. Instead, when a frequently-revised monograph is cataloged on a serial workform for convenience, GPO retains the SuDocs classification number assigned to the first (or earliest-received) monograph and adds a slash after the Cutter number.


Superintendent of Documents Classification Guidelines

Introduction to the Classification Guidelines
The Classification System: A Brief History
Structure of the Classification Number
Sorting in SuDocs Order
Example of a SuDocs Sort
Class Stems
Letter Author Symbols
New Agency Classes
Joint Publications from Different Agencies
Publications Prepared by One Agency for Another
Serials with Changing Publishers
Joint Publications Issued in Series
Subordinate Offices
First and Second Levels
Assignment of Classes
Third and Fourth Levels
Joint Publications from Different Subagencies
Name Changes and Reorganizations
Category Classes
Most Frequently Used Category Classes
.1 - Annual reports
.2 - General publications
.8 - Handbooks, manuals, and guides
.11 - Maps and Charts
.12 - Posters
Less Frequent Category Classes
.3 - Bulletins
.4 - Circulars
.5 - Laws
.6 - Regulations, rules, and instructions
.7 - Press releases
.9 - Bibliographies and Lists of Publications
.10 - Directories
.13 - Forms
.14 - Addresses
Cutter Numbers
Cutter Table and Its Use
Filing Order for Cutter Numbers
Slash Numbers
Selecting Cutter Words
Words to Avoid when Cuttering
Sets With a Collective Title
Foreign Language Editions
Numbers in Titles
Cuttering Acronyms and Initialisms
Cuttering: Geographic Topics
Cuttering Related Documents Covering the Same Subject but Different
General Subjects and Geographic Terms
Cuttering Geographic Terms Using Personal Names
Cuttering Multi-Part Geographic Names
State Cutter Numbers
State Cutter Numbers Table
Additions to Book Numbers
Year Format
Dates for Revised Editions
Punctuation in Dates or Date Ranges
Volume, Part, Chapter, and Section Numbers
Volume Number and Date: Which Comes First?
Volume Number Followed by Date
Date Followed by Volume Number
Words and Abbreviations
Foreign-language Publications
Multiple Word Phrases in a Suffix
Multiple Versions of a Publication
Corrected Copies of Numbered Volumes
Standard Abbreviations and Words
State Abbreviations
Classes by Publication Type
Preliminary, Draft, and Final Reports
Preprints and Separates
Summaries and Executive Summaries
Electronic Products
Sets with Multiple Publication Types
Monographic Series
Identifying a Monographic Series
Assigning New Series Classes
Series Related to Existing Classes by Subject
Structure of the Series Class
Departmental Series vs. Bureau Series
Series Book Numbers
Series Numbering
Unusual Series Numbering
Series Numbering and Revised Editions
Numbering system changes
Two series on one publication
Series number vs. Agency control number
Letters and Phrases Appearing on Publications
Volumes, Parts, or Sections
Publications Which Are Not Serials or Series
Multipart Monographs versus Series
Other Situations
Continuing Resources
Identifying a Continuing Resource
Integrating Resources
Assigning New Continuing Resource Classes
Works Related to Category Classes
Works Related to Existing Classes by Subject
New Classes to Reflect Changes for Existing Serials
Serials within Series: Separate Class Approach
Serials with a Constant Series Number
Cuttering a Serial or, When Not to Establish a New Class Stem for a Serial
Serials within Series: Cuttering Approach
Publications of Short Duration
Other cases for Cuttering
Serials Designation
Number 1 for First Month Appears Annually
Date incorporated in Series Number
Volume and Number
Annual Publications
Semiannual Publications
Publications Issued Three or More Times a Year
Variations in Publication Cycles
Release Date vs. Coverage Date
Special Issues of Serials
Frequently Revised Monographs Cataloged as Serials
Presidential Publications
Presidential Committees and Commissions
Presidential Commissions vs Presidential Initiatives
Permanent Agencies Reporting to the President
Vice President of the United States
Congressional and Legislative Branch Publications
Y 4. - Congressional Committee Publications
Constructing the Committee Designation
Reorganized Committees and Name Changes
Y 4. Committee Print or Y 1. Report?
Joint Hearings
Publications Prepared by One Committee for the Use of Another
Individual Book Numbers
House Book Numbers
Numbered and Unnumbered Documents in One Class
Senate Book Numbers
Cutter Numbers
Multipart Works
Errors in Numbering on Publications
Y 1.-: - Congress as a Whole, House and Senate as a Whole
Individual Book Numbers
House and Senate Documents and Reports
Y 1.1/2: - U. S. Congressional Serial Set
Y 1.2/5: - United States Code
Boards, Commissions, and Independent or Temporary Committees Established by Congress
Executive Branch Independent Agencies
EX 1.2:- Limited Duration Executive Branch Independent Agencies (Commissions, Committees, and Boards)
Y 3. - Boards, Commissions, and Independent or Temporary Committees
Agency Designations
Category and Series Designations
Related Series or Subjects
Individual Book Numbers
Y 3.2: - Limited Duration Boards, Commissions, and Independent Committees
Cutter Numbers
Y 10: and Y 11: - Subordinate Offices
X 1.1: - Congressional Record
XJH: and XJS: - House and Senate Journals
Y and X General Issues
Serial Publications
Star Prints
U.S. Participation in International Organizations
Cartographic Resources
Category Classes for Maps and Charts
General Rules
U.S. Geological Survey Maps
Map Reference Numbers
Northwest (NW) Quadrant
Northeast (NE) Quadrant
Southwest (SW) Quadrant
Southeast (SE) Quadrant
Edition Date
Bureau of Land Management Maps
U.S. Forest Service Maps
Revision Dates
National Ocean Service Nautical Charts
Map Types
Classification Guidelines for Digital Reproductions
Classification by Type of Digital Reproduction

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