MIL-STD-40051-2, explained

MIL-STD-40051-2 was the Army's standard for page-based technical manuals, Part 2 of the two-part MIL-STD-40051. The ASSIST-QuickSearch record kept by the Defense Logistics Agency titles it Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs), dates the base document October 15, 2004, and shows it canceled on March 25, 2025 and superseded by MIL-STD-40051E. Where Part 1 governed Interactive Electronic Technical Manuals (IETMs), Part 2 governed the manual a soldier or Marine holds or opens as a PDF: how it is divided into chapters and work packages, what comes before the first text page and after the last, how figures and tables are numbered and placed, and how the whole thing is tagged for delivery. People search for it as "mil-std-40051-2", "mil-std 40051/2c", and "40051-2d", and the slash and hyphen forms name the same document. This post covers the scope, the work package structure on paper, front matter and rear matter, illustration and table rules, the revision history through Revision D, the cancellation, and how Part 2 differed from Part 1. The wider family of standards is covered in the post on the U.S. technical manual standards.

What MIL-STD-40051-2 covered

The ASSIST scope says the standard set content, style, and format requirements for technical manuals for major weapon systems and their related systems, equipment, and components, across operator and maintenance manuals, depot and national maintenance work requirements, preventive maintenance publications, lubrication orders, ammunition data sheets, software manuals, hand receipts, and technical bulletins, at all maintenance levels through depot overhaul. Two sentences in the scope matter for searchers. The record says the standard treats electronic technical manuals as synonymous with page-based manuals, so an ETM under this family is a page-based manual shown on a screen, not an IETM. And it points to MIL-HDBK-1222G for preferred style and format, to be followed unless it conflicts with the standard. The record lists the Army Materiel Command, Life Cycle Sustainment Division as lead standardization activity, preparing activity, and Army custodian, coordination level Limited, and Distribution Statement A on every entry.

The text quoted in this post is the Change 3 edition of March 21, 2008, which EverySpec hosts as a 3.17 megabyte file; the later revisions are larger files on the same site and on ASSIST. The header says it supersedes the Change 2 edition of July 30, 2007 and MIL-PRF-63003B(TM) with Amendment 1 of November 15, 2001, which places the page-based part in a line of Army performance specifications. The foreword says the standard is approved for the Department of the Army and the Department of the Marine Corps and available to all departments and agencies of the Department of Defense (DoD), covers operation and maintenance at all levels through depot including Depot Maintenance Work Requirements (DMWRs) and National Maintenance Work Requirements (NMWRs), and names the two parts of the book form. Paragraph 1.1 says the requirements "can be used to develop TMs in paper, paged-based manuals," and paragraph 1.2 explains the service prefixes (A), (N), (MC), and (F) that limit individual paragraphs.

Section 4 gives the structure. Paragraph 4.1 places style and format in 4.7 and the technical content in six appendixes: B for general information, equipment description, and theory of operation; C for operator instructions; D for troubleshooting procedures; E for maintenance instructions; F for the Repair Parts and Special Tools List (RPSTL); and G for supporting information. Paragraph 4.2 says Appendix A, Content Selection Matrixes, lists the content required for each type of manual, and that each manual must provide the maintenance coverage prescribed by the Maintenance Allocation Chart (MAC). Paragraph 4.3 gives the acquiring activity responsibility for tailoring through those matrixes, and section 6.2 says an acquisition document should cite the standard, MIL-HDBK-1222, MIL-STD-2361 and MIL-HDBK-2361, and the filled-out matrixes.

Work packages on paper

Paragraph 4.7.2 gives the hierarchy of a page-based manual: volumes if required, chapters, work packages, paragraphs, subparagraphs, and steps, with the rule that each division used should have at least two occurrences. Paragraph 4.7.2.1 says a manual is divided into volumes when its printed pages exceed 1,500 pages or 750 sheets, and that a pocket manual or pocket volume may not exceed 200 pages or 100 sheets. Each volume of a series carries the manual number on its cover and every page, its own title block page and table of contents, and rear matter with at least the DA Forms 2028 and an authentication page. Separate volumes shall not be used to distinguish models of equipment. Paragraph 4.7.2.2 says chapters divide the manual into functional information and that each chapter is made of one or more work packages.

Paragraph 4.7.2.3 says work packages logically divide the data into functional descriptive or task-oriented information and shall begin on a right-hand page. Paragraph 4.7.2.3.1 says they should not exceed 30 pages, so a series of maintenance tasks can be split, for example removal and installation of a gun turret in one work package and disassembly and reassembly in a second, unless the split would degrade usability. Paragraph 4.7.2.3.2 says a work package contains a title block, initial setups, descriptive information, operating tasks, and maintenance tasks, which divide further into paragraphs, procedural steps, tables, lists, warnings, cautions and notes, and supporting illustrations. Paragraph 4.7.2.3.3 lists the factors that decide how coverage is divided: a work package the standard requires, one the content selection matrix requires, operational modes or maintenance levels, configuration differences that change a task, the 30-page limit, usability, and different initial setup information. Paragraph 4.7.9 then covers work package identification information, sequential numbering, page numbering, and the unique work package identification number that is assigned once and never changed.

Delivery is digital even for a paper manual. Paragraph 4.4 says manual data prepared and delivered digitally shall be Extensible Markup Language (XML) tagged using the Document Type Definitions (DTDs) and XML Stylesheet Language (XSL) or style sheets in accordance with MIL-STD-2361, with a sample source file in MIL-HDBK-1222. Paragraph 4.5 says the DTD is mandatory, that the XSLs interpret style and format, and that style sheets may be used to produce the final reproducible paper copy. Paragraph 4.6 says the DTD and style sheets come from the Army SGML Registry and Library through the methods in MIL-STD-2361. Paragraph 4.7 names the U.S. Government Printing Office Style Manual as the general guide for capitalization, punctuation, and spelling of nontechnical words.

Page size, type, and foldouts

Paragraph 4.7.3 sets type: a minimum of 8 point for a regular manual and 6 point for logbooks, pocket manuals, and graphics, proportionally spaced, with all-capital text limited to major headings, acronyms, and equipment markings. Paragraph 4.7.4 says the manual is prepared in a size the acquiring activity selects from TABLE I and that page orientation shall be consistent through a manual, a point the standard says matters more as manuals are read on screens. TABLE I lists four styles: pocket at 4 by 5 and a half inches, logbook at 6 and a half by 9 and a half, standard at 8 and a half by 11 with a maximum printing area of 7 by 10 inches, and double standard at 17 by 11.

Paragraph 4.7.5 governs foldouts. They are the same height as regular pages in the standard-size manual only, folded 2, 4, or 6 times depending on width, with a blank apron wide enough for the user to view the data while reading text elsewhere. Foldouts shall not be used in RPSTLs or operator-only manuals. Paragraph 4.7.15 adds that foldout illustrations are not placed inside work packages but follow the last work package, the glossary, or the alphabetical index, whichever ends the manual or volume.

Front matter

Paragraph 5.2.1 lists the front matter in a fixed order: front cover, promulgation letter for Marine Corps manuals, warning summary, change transmittal page if applicable, list of effective pages and work packages, title block page, table of contents, and How To Use This Manual information. Paragraph 5.2.1.1 says a front cover is prepared for every manual, DMWR, and NMWR, and lists its content in order: security classification when required, the manual number, a National Overhaul Standard statement for depot documents, the title, the National Stock Number, and the End Item Code when required.

Paragraph 5.2.1.3 says that, when required, a warning summary is prepared for every manual that contains warnings and appears on the first right-hand page after the front cover. It holds first aid data, which must begin by referencing FM 4-25.11, explanations of every general safety and hazardous materials icon used in the manual, and descriptions of the general safety and hazardous materials warnings that have major impact throughout the manual, in the order first aid, warning icons, warning descriptions, hazardous materials icons, hazardous materials descriptions. Only warnings that meet that test belong in the summary. Paragraph 5.2.1.4 says each change gets an unnumbered change transmittal page after the warning summary, listing every page and work package changed, added, deleted, or superseded. Paragraph 5.2.1.5 says a list of effective pages and work packages is transmitted with the basic manual and every change or revision, immediately after the warning summary, for technical manuals, RPSTLs, DMWRs, and NMWRs.

Paragraph 5.2.1.8 says the table of contents lists all chapters, work packages, figures, and tables, with the exact same titles in the same order as they appear, figures and tables listed under their work package except foldouts, which go at the end. The How To Use This Manual information is listed with its page number; the warning summary is not listed. The table of contents begins on the first available page after the title block page, and in a multi-volume set Volume 1 carries a complete table for the whole set. Paragraph 5.2.1.9 says How To Use This Manual information, prepared for all manuals except RPSTLs and DMWRs and NMWRs, starts on the page after the table of contents and explains the format and organization without repeating instructions from the chapters, with a reference to the associated RPSTL for all manuals except operator manuals and, for troubleshooting manuals, an explanation of how symptom indexes and malfunction codes lead to the procedures.

Rear matter

Paragraph 5.2.2 lists the rear matter, as applicable: glossary, alphabetical index, DA Forms 2028 for reporting errors and recommending improvements, authentication page, foldout pages, blank forms, and back cover, with the glossary, index, and foldouts not required for an RPSTL. Paragraph 5.2.2.1 says a glossary is prepared only when terms are uncommon and not defined in the text or in the Army, DoD, or a standard dictionary; it begins on a separate right-hand page before the index and numbers its pages Glossary-1, Glossary-2, and so on. Paragraph 5.2.2.2 says an alphabetical index is prepared unless the acquiring activity specifies otherwise, may be an index of work packages only or a detailed index, sits at the end of the manual before the sample DA Form 2028, and numbers its pages Index-1, Index-2, and so on.

Paragraph 5.2.2.3 is the one most readers of Army manuals recognize: one filled-out sample copy of DA Form 2028, provided by the acquiring activity, and a minimum of three blank forms with the manual number, date, and title shall be included before the authentication page of every unclassified manual, except oversize manuals, pocket-size manuals, and manuals under eight pages. Paragraph 5.2.2.4 says the authentication page is the last printed text page, or the last before any foldouts, and that for changes the authentication block goes at the end of the change transmittal sheet. Paragraph 5.2.2.7 says the outside back cover is blank except for pocket-size manuals, which carry the manual number, and classified manuals, which carry classification markings; a metric conversion table goes on the inside back cover when applicable.

Illustration and table rules

Paragraph 4.7.27 covers graphics. The format is specified by the acquiring activity under AR 25-30, and the types are line drawings, photographs, engineering drawings, diagrams, charts and graphs, and tools and test equipment illustrations. Paragraph 4.7.27.2.1 says line drawings support the procedures and the RPSTLs, and that index numbers used to identify parts are assigned clockwise beginning at 11 o'clock, except in preventive maintenance procedures. Paragraph 4.7.27.2.3 allows film or digital photographs, requires that all be delivered as digital photographs, and leaves their acceptability to the acquiring activity. Paragraph 4.7.27.3.6 forbids procedural steps on illustrations.

Paragraph 4.7.27.4.1 says figure numbers appear on all illustrations except inline graphics, run sequentially within each work package from 1, precede the title, and are kept separate from the graphic so the text can be searched; 4.7.27.4.2 numbers RPSTL figures sequentially within the RPSTL instead. Paragraph 4.7.27.4.8 says illustrations are black and shades of black unless the acquiring activity specifies otherwise, with prior written approval for color from the Army Publishing Directorate. Paragraph 4.7.15 places illustrations as close to their text reference as possible, prefers the same or facing page, allows a 90 degree counterclockwise rotation, and puts pocket manual text on right-hand pages with illustrations facing on the left.

Paragraph 4.7.13 covers tables and lists. Tables are inserted on the same page as, or as soon as possible after, their first reference; a full-page landscape table is positioned so the page is rotated 90 degrees clockwise to read it. Tables that are referenced or listed in the table of contents are numbered consecutively within each work package from 1 and carry a title. Paragraph 4.7.13.4 says tables designated standard information permit no deviation in number of columns, column titles, or format, because the style sheet generates them, while non-standard tables follow MIL-HDBK-1222 but must still include the data the appendixes require. Paragraph 4.7.13.5 lists the standard information tables: Controls and Indicators, Checking Unpacked Equipment, Preventive Maintenance Checks and Services, Classification of Material Defects, Overhaul and Retirement Schedule, Depot Mobilization Requirements, Repair Parts List, and Special Tools List.

Revision history, cancellation, and the difference from Part 1

The ASSIST record lists ten entries, in step with Part 1: the base document of October 15, 2004 at 422 pages; Change 1 on May 12, 2006 at 404 pages; Change 2 on July 30, 2007 at 428 pages; Change 3 on March 21, 2008 at 434 pages; Revision A on July 21, 2010 at 466 pages; Revision B on November 30, 2012 at 496 pages; Revision C on December 15, 2015 at 584 pages; Revision D on March 1, 2021 at 593 pages; Revision D Change 1 on November 22, 2021 at 611 pages; and the one-page Revision D Notice 1 cancellation of March 25, 2025. EverySpec carries the texts under the slash form of the number: Revision A as an 11.51 megabyte file, Revision B at 14.01 megabytes, and Revision C at 35.79 megabytes, each still marked Active on the mirror. The file EverySpec posts under the 2004 base entry is 600.67 kilobytes, and its text is titled Technical Manuals, Introductory Information with Theory of Operation and refers to DTDs and Formatting Output Specification Instances, so it is the Part 2 of the older multi-part MIL-STD-40051, not the 422-page 2004 base document on ASSIST.

The MIL-HDBK-1222 record shows the handbook revised on the same dates, Revision F on December 15, 2015 for Revision C and Revision G on March 1, 2021 for Revision D, and says the handbook is guidance only and cannot be cited as a requirement. The ASSIST record for MIL-STD-40051 shows the successor: Revision E, dated March 25, 2025 at 782 pages, with Change 1 on July 30, 2025 at 784 pages, active, next review due July 29, 2030. The Revision E scope says the standard applies regardless of output format and uses IETM and ETM to mark output-specific requirements, so the page-based rules described here now live in the same document as the IETM rules.

That is also the cleanest statement of how the two parts differed. The record for Part 1 adds functionality to the list of things it governs, and the Part 1 text carries an Appendix A functionality matrix, inner and outer screen shells, and alerts displayed as dialog boxes, which Part 2 never had. Part 2 carries the things a screen does not need: trim sizes, foldouts, right-hand page starts, a 30-page work package limit, page numbering for front and rear matter, DA Forms 2028, and an authentication page. The two parts shared the content appendixes, the work package concept, the content selection matrixes, the DTD under MIL-STD-2361, and the handbook, and they were issued and canceled on the same days. The IETM side is covered in the post on MIL-STD-40051-1.

What to check

• Which revision does the contract cite? MIL-STD-40051/2C is the December 15, 2015 text; Revision D Change 1 of November 22, 2021 is the last; the 2004 base on ASSIST is 422 pages and is not the short file some mirrors post under that date.
• Has the acquiring activity decided whether deliveries stay under the canceled Part 2 or move to MIL-STD-40051E, where the same requirements carry the ETM label?
• Does the delivered manual follow the front matter order of paragraph 5.2.1, with the warning summary on the first right-hand page and the list of effective pages and work packages immediately after it?
• Does every unclassified manual carry a filled-out sample DA Form 2028 and at least three blank forms before the authentication page, unless it falls under the pocket, oversize, or under-eight-pages exceptions?
• Do work packages begin on right-hand pages, stay near the 30-page limit, and number their figures and tables from 1 within each work package?
• Is the manual XML tagged to the DTD under MIL-STD-2361, and are the filled-out content selection matrixes attached to the contract as paragraph 6.2 expects?

Azcuna's TRACE is one offline viewer for S1000D, MIL-STD-3001 XML, and PDF technical manuals. It keeps the source location and the markings of everything it shows and never modifies the source. It was proposed to NAVAIR under Navy SBIR Phase I topic DON26BZ05-NV078, and the proposal was submitted on September 23, 2026.

Questions people ask

What is MIL-STD-40051-2?

MIL-STD-40051-2 was Part 2 of the Army's two-part technical manual standard, titled Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs). The ASSIST record says it set technical content, style, and format requirements for technical manuals covering major weapon systems and their equipment at all maintenance levels through depot overhaul, and that it treats the term electronic technical manual as synonymous with page-based manual. The base is dated October 15, 2004 and ASSIST shows it canceled on March 25, 2025.

What is MIL-STD-40051/2C?

MIL-STD-40051/2C is Revision C of Part 2, dated December 15, 2015. ASSIST lists it at 584 pages, and EverySpec hosts the 35.79 megabyte file with the slash form of the number in its title. Revision C sat between Revision B of November 30, 2012 and Revision D of March 1, 2021. MIL-HDBK-1222 Revision F, also dated December 15, 2015, was the matching style guide. A contract citing 40051/2C is citing the 2015 text.

Is MIL-STD-40051-2 still active?

No. The ASSIST record kept by the Defense Logistics Agency shows status Canceled, a Revision D Notice 1 cancellation dated March 25, 2025, and the title suffix S/S By MIL-STD-40051E. MIL-STD-40051 Revision E, dated the same day with Change 1 on July 30, 2025, is the active replacement and covers page-based and interactive output in one document, using the label ETM for page-based requirements.

What is MIL-STD-40051-2D?

Revision D is the last revision of Part 2. ASSIST lists Revision D dated March 1, 2021 at 593 pages and Revision D Change 1 dated November 22, 2021 at 611 pages, followed by the one-page Revision D Notice 1 cancellation of March 25, 2025. MIL-HDBK-1222 Revision G, dated March 1, 2021, is the handbook ASSIST says is meant to be used with MIL-STD-40051-1 and -2 Revision D.

What front matter does MIL-STD-40051-2 require?

Paragraph 5.2.1 of the Change 3 text lists the front matter in order: front cover, a promulgation letter for Marine Corps manuals, warning summary, change transmittal page when applicable, list of effective pages and work packages, title block page, table of contents, and How To Use This Manual information. The warning summary goes on the first right-hand page after the cover and includes first aid data, warning icons and descriptions, and hazardous materials icons and descriptions.

What rear matter does MIL-STD-40051-2 require?

Paragraph 5.2.2 of the Change 3 text lists, as applicable, a glossary, an alphabetical index, DA Forms 2028 for reporting errors and recommending improvements, an authentication page, foldout pages, blank forms, and the back cover. The manual carries one filled-out sample DA Form 2028 and at least three blank ones before the authentication page, which is the last printed text page. The back cover is blank except for pocket-size and classified manuals.

How long can a work package be in MIL-STD-40051-2?

Paragraph 4.7.2.3.1 of the Change 3 text says work packages should not exceed 30 pages, to help usability and the revision process, and that a series of maintenance tasks can be divided into two or more work packages unless separating them would degrade usability. Paragraph 4.7.2.3 requires each work package to begin on a right-hand page, and 4.7.2.3.2 says it contains a title block, initial setups, descriptive information, operating tasks, and maintenance tasks.

What page sizes does MIL-STD-40051-2 allow?

TABLE I in paragraph 4.7.4 of the Change 3 text gives four styles: pocket at 4 by 5 and a half inches, logbook at 6 and a half by 9 and a half, standard at 8 and a half by 11 with a 7 by 10 inch printing area, and double standard at 17 by 11. The acquiring activity selects the size. Minimum type is 8 point for a regular manual and 6 point for logbooks, pocket manuals, and graphics. Foldouts are folded 2, 4, or 6 times and are not used in parts lists or operator-only manuals.

How does MIL-STD-40051-2 differ from MIL-STD-40051-1?

Both parts were issued October 15, 2004, share the content appendixes and the work package structure, and were canceled together on March 25, 2025. Part 2 governs output on pages: trim sizes, foldouts, right-hand page starts, front and rear matter, DA Forms 2028, and figure placement. Part 1 governs IETMs and adds the Appendix A functionality matrix, screen shells, and alerts shown as dialog boxes. The ASSIST scope for Part 2 says electronic technical manual means a page-based manual.

Sources

1. 1MIL-STD-40051, Part 2, Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) (S/S By MIL-STD-40051E) (ASSIST-QuickSearch Document Details) · Defense Logistics Agency, ASSIST-QuickSearch
2. 2MIL-STD-40051, Preparation of Digital Technical Information for Technical Manuals (TMs) (ASSIST-QuickSearch Document Details) · Defense Logistics Agency, ASSIST-QuickSearch
3. 3MIL-STD-40051, Preparation of Digital Technical Information for Interactive Electronic Technical Manuals (IETMs) (ASSIST-QuickSearch Document Details) · Defense Logistics Agency, ASSIST-QuickSearch
4. 4MIL-HDBK-1222, Guide to the General Style and Format of U.S. Army Work Package Technical Manuals (ASSIST-QuickSearch Document Details) · Defense Logistics Agency, ASSIST-QuickSearch
5. 5MIL-STD-40051/2 (w/Change 3), Department of Defense Standard Practice: Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, March 21, 2008, via EverySpec
6. 6MIL-STD-40051/2C, Department of Defense Standard Practice: Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, December 15, 2015, via EverySpec
7. 7MIL-STD-40051/2B, Department of Defense Standard Practice: Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, November 30, 2012, via EverySpec
8. 8MIL-STD-40051/2A, Department of Defense Standard Practice: Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, July 21, 2010, via EverySpec
9. 9MIL-STD-40051/2, Department of Defense Standard Practice: Preparation of Digital Technical Information for Page-Based Technical Manuals (TMs) · Department of Defense, October 15, 2004, via EverySpec

Where this shows up in our work

• TRACE, the offline S1000D and IETM viewer opens S1000D, MIL-STD-3001 and PDF technical manuals on a tablet with every marking intact.
• ELLMENT, the offline LLM for E-2D crews answers a crew's question from the aircraft's own manuals and cites the page, with no network.