# IEC 61355

The standard IEC 61355-1 Classification and designation of documents for plants, systems and equipment describes rules and guidelines for the uniform classification and identification of documents based on their characteristic content of information.
It is applied for all documents within the life cycle of a technical products like plants, systems or equipment. It also includes non-technical documents. The main application is the construction, erection and operation of industrial plants where the number of documents of all engineering disciplines may sum up to some 100,000 documents.
During 2024, the new cross-standard ISO/IEC 81355 will be published and will replace the second edition of IEC 61355-1 published in 2008. The new standard will switch from "document classification" to "information classification" methods.

## Classification code

The standard provides with the document kind classification code (DCC) a structured letter-code for the classification of any kind of document.
A public access database IEC 61355 DB is available in order to facilitate the individuation of the correct code to be applied to a document
The document kind classification code consists of three code-letters A1, A2, A3, with the prefix "&".
* A1 Letter code for technical area class
* A2 Letter code for main class
* A3 Letter code for sub-class
The letter code A1 is optional, if all documents are from the same technical area. The letter codes A2 and A3 are identical for all technical areas.

## Technical Areas

The technical areas are:
| A1 | Technical area |
| A | Overall management |
| B | Overall technology |
| C | Construction engineering |
| E | Electrical engineering, instrumentation and control engineering |
| M | Mechanical engineering (normally including process engineering)) |
| P | Process engineering (only if separation from M is required)) |

## Classes

The main classes are:
| A2 | document kind classes, main classes |
| A | Documentation describing documents |
| B | Management documents |
| C | Contractual and non-technical documents |
| D | General technical information documents |
| E | Technical requirement and dimensioning documents |
| F | Function describing documents |
| L | Location documents |
| M | Connection describing documents |
| P | Object listings |
| Q | Quality management documents; safety-describing documents |
| T | Geometry-related documents |
| W | Operation records |

## Main classes and subclasses

Table of main classes and subclasses
| A2 A3 | Document kind classes, main class and subclass | Examples of document kinds |
| A | Documentation describing documents | |
| AA | Administrative documents | Cover sheet Title sheet |
| AB | Lists (regarding documents) | List of documents List of contents Index |
| AC | Explanatory documents (regarding documents) | Document description Documentation structure diagram |
| AD ... AY | Reserved for future standardization | |
| AZ | Free for user | |
| B | Management documents | |
| BA | Registers | Vendor list Supplier list Distribution list |
| BB | Reports | Meeting report Status report Technical report Damage report Installation report Commissioning report Handing over protocol |
| BC | Correspondence | Letter Note |
| BD | Project control documents | Document interchange list Time sheet |
| BE | Resource planning documents | Time schedule Activity network plan Resource load diagram |
| BF | Dispatch, storage and transport documents | Dispatch specification Shipping list Packing list Airway bill Bill of lading Certificate of origin Storage specification Transport specification |
| BG | Site planning and site organization documents | Site specification for personnel |
| BH | Documents regarding changes | Change notification Change request |
| BJ ... BR | Reserved for future standardization | |
| BS | Security documents | Escape plan Emergency instruction Fire protection plan Noise protection plan |
| BT | Training specific documents | Training description |
| BU ... BY | Reserved for future standardization | |
| BZ | Free for user |
| C | Contractual and nontechnical documents | |
| CA | Inquiry, calculation and offer documents | Inquiry Calculation sheet (commercial) Offer Letter of intent Letter of acceptance |
| CB | Approval documents | Approval application Acceptance/ authorization License |
| CC | Contractual documents | Contract Final acceptance certificate Terms of delivery |
| CD | Order and delivery documents | Order Delivery note |
| CE | Invoice documents | Invoice |
| CF | Insurance documents | Insurance policy Damage assessment |
| CG | Warranty documents | Certificate of guarantee |
| CH | Expertises | Expertise |
| CJ ... CY | Reserved for future standardization | |
| CZ | Free for user |
| D | General technical information documents | |
| DA | Data sheets | Data sheet Dimension drawing |
| DB | Explanatory documents | System description Structure diagram Description of designation system |
| DC | Instructions and manuals | Manufacturing instructions Installation instructions Operating instructions Inspection instructions Maintenance instructions Operation manual |
| DD | Technical reports | Technical report R&D report |
| DE | Catalogues Advertising documents | Catalogue Product leaflet |
| DF | Technical publications | Technical publication |
| DG ... DY | Reserved for future standardization | |
| DZ | Free for user |
| E | Technical requirement and dimensioning documents | |
| EA | Legal requirement documents | Building regulation Operation decree Environmental decree |
| EB | Standards and regulations | IEC standard ISO standard |
| EC | Technical specification / requirement documents | Requirement specification Technical specification Consumer list Component / device list of instrumentation and control equipment Measuring point and criteria list List of motors and loads Test specification Material specification |
| ED | Dimensioning documents | Calculation sheet (technical) |
| EE ... EY | Reserved for future standardization | |
| EZ | Free for user |
| F | Function-describing documents | |
| FA | Functional overview documents | Network map |
| FB | Flow diagrams | Block diagram Process flow diagram (PFD) Piping and instrumentation diagram (P & ID) Utility flow diagram (UFD) |
| FC | MMI layout documents (MMI = man-machine interface) | Screen display layout drawing |
| FD | Reserved for future standardization | |
| FE | Function descriptions | Function description |
| FF | Function diagrams | Function diagram Logic function diagram Function chart Sequence chart Equivalent circuit diagram Time sequence chart |
| FG ... FN | Reserved for future standardization | |
| FP | Signal descriptions | Signal list |
| FQ | Setting value documents | Setting list |
| FR | Reserved for future standardization | |
| FS | Circuitry documents | Circuit diagram |
| FT | Software specific documents | Program diagram Code list Design description |
| FU ... FY | Reserved for future standardization | |
| FZ | Free for user | |
| L | Location documents | |
| LA | Exploitation and survey documents | Ground plan |
| LB | Earthwork and foundation work documents | Excavation plan Foundation drawing |
| LC | Building carcass documents | Reinforcement plan Static drawing |
| LD | On-site location documents | Arrangement drawing (site) Site plan Installation drawing (site) Installation diagram (site) Cable routing drawing (site) Earthing plan, drawing (site) |
| LE ... LG | Reserved for future standardization | |
| LH | In-building location documents (also applied for ships, aircraft, etc.) | Arrangement drawing (building) Building drawing Installation diagram (building) Cable routing drawing (building) Earthing drawing (building) |
| LJ ... LT | Reserved for future standardization | |
| LU | In/on-equipment location documents | Arrangement drawing (equipment) Assembly drawing |
| LV ... LY | Reserved for future standardization | |
| LZ | Free for user | |
| M | Connection-describing documents | |
| MA | Connection documents | Connection diagram Connection table |
| MB | Cabling or piping documents | Cable diagram Cable pulling card Piping list |
| MC ... MY | Reserved for future standardization | |
| MZ | Free for user | |
| P | Object listings | |
| PA | Material lists | Material list |
| PB | Parts lists | Parts list Spare parts list Label list |
| PC | Item lists | Item list |
| PD | Product lists and product type lists | Product list Product type list |
| PE | Reserved for future standardization | |
| PF | Function lists | Function list |
| PG ... PK | Reserved for future standardization | |
| PL | Location lists | Location list |
| PM ... PY | Reserved for future standardization | |
| PZ | Free for user | |
| Q | Quality management documents and safety-describing documents | |
| QA | Quality management documents | Quality manual Quality plan Quality record Quality guideline Audit plan Audit report Non-conformity report Declaration of conformity |
| QB | Safety-describing documents | Safety study Risk assessment |
| QC | Quality verifying documents | Test certificate Material certificate Test report Fault report |
| QD ... QY | Reserved for future standardization | |
| QZ | Free for user | |
| T | Geometrical form describing documents | |
| TA | Planning drawings | Concept drawing Design drawing |
| TB | Construction drawings | Dimension drawing Interface drawing Exploded-view drawing 3D-drawing |
| TC | Manufacturing and erection drawings | Manufacturing drawing Drilling plan Welding plan |
| TD ... TK | Reserved for future standardization | |
| TL | Arrangement documents | Layout drawing |
| TM ... TY | Reserved for future standardization | |
| TZ | Free for user | |
| W | Operational protocols and records | |
| WA | Set point documents | Batch recipe |
| WB ... WS | Reserved for future standardization | |
| WT | Logbooks | Operational log Maintenance and modification log Test log |
| WU ... WY | Reserved for future standardization | |
| WZ | Free for user | |
Source: IEC 61355–1