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Spectrum advice: Re-numbering your collections – why it might not be worthwhile

This Spectrum advice fact sheet explores re-numbering, suggests why it is a poor use of resources, and gives some examples of numbering problems and their solutions. It also places numbering and re-numbering in the context of the requirements of the Accreditation Scheme for Museums and Galleries in the UK.

  • Introduction
  • Spectrum and Museum Accreditation
  • Why is numbering museum objects important?
  • Why it might not be a good idea to re-number your collections
  • Some common numbering problems and their solutions

Museums are often faced with documentation numbering systems that seem muddled and inconsistent. Re-numbering collections is often suggested when:

  • Collections that were distinct are merged (e.g. the archaeology collection is merged with the social history collection to become the human history collection or two collections from different museums are merged)
  • Accession numbers contain information about objects that is no longer relevant e.g. numbers contain information about storage locations or object types (such as ‘P’ for photographs and ‘C’ for costume).

Some museums think that a solution to this is to start again and give every object in the collection a new number. This is usually a bad idea and when the Collections Trust is approached by museums considering re-numbering we always advise against it.

Spectrum and Museum Accreditation

The structure of a museum documentation system usually reflects Spectrum, the UK museum collections management standard. It is a requirement of the Museum Accreditation Scheme that the nine Spectrum ‘Primary Procedures’ are in place in Accredited museums – see Accreditation Standard, Requirement 2.7.

Spectrum primary procedures are the foundation of a basic museum documentation system. Numbering of collections takes place during the following Spectrum procedures: Object entry, Acquisition and accessioning, Inventory and Documentation planning. It will also take place during the Loans in (borrowing objects) and Loans out (lending objects).

In all of the above procedures, different types of number are applied eg entry numbers, accession numbers, loans in and loans out numbers. Re-numbering of collections is usually suggested with reference to Accession numbers, which are the focus of this fact sheet. However the same numbering principles and reasons for not re-numbering can be applied to all type of museum object number.

A documentation procedural manual is also a requirement of the Museum Accreditation Scheme. You should record the formats of your current numbering systems in your procedural manual, and if possible descriptions of previous numbering systems. For more about procedural manuals and their contents, see the procedural manual template.

For more about numbering and numbering systems see the Spectrum advice: numbering fact sheet.

Why is numbering museum objects important?

Spectrum and the Museum Accreditation Scheme require that all objects in the collections are allocated with a unique number, and in the case of the long term collections, a unique accession number. Accession numbers, once allocated and physically attached to the museum object, create a link between the object and its associated information. If that link is broken, for example because the number has fallen off the object, the link between the object and its information is lost. This means that the museum no longer knows what the object is, where it is, or how it was acquired, and will have to spend valuable time and resources re-establishing the link between object and information in an inventory procedure.

Accession numbers don’t need to be ‘intelligent’. An accession number is only a code; its sole purpose is to help you find information about the object in your documentation system. The number usually contains reference to the year of accession, or it may just be a running sequence of numbers. It does not need to contain additional information such as storage location or object type or collection – information like this is stored in fields in your cataloguing system, which in most museums is electronic.

Accession numbers are attached to objects using standard labelling and marking techniques, see the labelling and marking guides in the popular resources panel.

Why it might not be a good idea to re-number your collections

Numbering systems don’t have to be neat to be effective. 

An accession number links the museum object to its information. If you are able to pick up an object in your store, look at the accession number and then locate all the information relating to it then you don’t have a problem with your numbering system.

It doesn’t matter if from 1920 to 1950 your accession numbers were written as ‘13267; 13268; 13269; 13270’, and from 1950 they changed to ‘1950.1; 1950.2; 1950.3’. Similarly, it doesn’t matter if three different departments within your museum started their own numbering systems or used different types of number for different types of object. The accession number is only a code for linking the object to the information about it – as long as the code is unique to every object and links the object to its documentation then formats do not matter.

You may need or want to change your numbering system, for example if you have been using running numbers and these have got too long. However, you can do this from today onwards, you do not need to go back and change existing numbering systems.

Old documentation is important

Old accession registers are rarely tidy or consistent, and may well not be organised in a way that reflects the organisation of the collection today. However, they were written as they were for a reason and are very important records; they are often the most original source of  information you have about your collection. Old accession numbers can be significant and often give us information about how the collector perceived the collection, or how the collection was organised. An accession register and its accompanying numbering system is a historical document; it tells its own story. It does not need to be re-written, and should never be discarded.

Re-numbering is a huge task

Re-numbering collections doesn’t involve just allocating a new number to every object in a database or catalogue. You will also have to make decisions about how you are going to link your old and new numbers. Are you going to mark each object with its new number? Are you going to cross-reference all your existing documentation to the new number? Re-numbering is a huge task. Do you have the resources to dedicate to a task that is simply replacing one unique code with a different unique code?

You may just be creating another problem for the future

If you decide that your collection must be re-numbered, you are embarking on a major project. Do you have the time and money to finish the project? If you don’t manage to re-number your entire collection and cross-reference every piece of documentation to the new number you will be creating a half finished numbering system that is going to be very confusing for people working in your museum in the future.

Some common numbering problems and their solutions

There are frequent gaps in our run of accession numbers, for example our register jumps from 1953.1 to 1953.3 with no entry for 1953.2. 

It does not matter that you have gaps in the numbering sequence in your accession register. This often happens if accession registers have been reconstructed retrospectively, or may happen through human error. For example, if objects were allocated numbers and marked with them but the information was never recorded in the register. It does not need that you need to change the old system and fill in the gaps. If there is a gap in your accession register you can annotate this with your initials and the date to explain what has happened. You could also create a catalogue record explaining why the number is ‘missing’. If you find what you suspect is 1953.2 then good practice is to give it a current accession number and enter it into your current accession register. You should then record that it was found in the store and is probably 1953.2.

In the past long-term loan items were given accession numbers. These loans have now been returned to their owners but there are still records for them in the accession register.

Under today’s standards loans should not be accessioned into the long term collection. However, if previously accessioned loans have been returned to their owners you do not need to re-number collections so that you do not have ‘redundant’ numbers in your register. Redundant numbers do not matter and can provide valuable information about the history of an object while it was in your care. Just note in the register that the object was taken in as a loan and has been returned, sign it and date it. You should back this up with a receipt in an object history or loans file from the owner saying they have had their object returned to them.

Nothing has been accessioned since 1993. Our accession numbers contain the year of accession (e.g. 2016.1) and we can’t begin to deal with the backlog because we don’t know always know in which year objects were acquired, so we can’t give them the correct accession number. 

Using an accession number format which contains the year (e.g. 1954.2) does not mean that objects have to be accessioned with a number for the year in which they were acquired. The aim of an inventory project is not to rebuild a ‘perfect’ accession register; it is to link objects with their information. If your accession numbers contain reference to the year, it is good practice to give an unnumbered object an accession number for the current year. If you think you know the date the object was acquired, that date should be entered in a separate field in your database or cataloguing system, with a note about the accession number having been allocated as a result of your inventory project. For example, if you were carrying out accessioning in 2016 for objects acquired in 1993 these objects should be given 2016 accession numbers and the acquisition date recorded separately as 1993.

We acquired a collection of objects from another organisation a few years ago. Each of the objects in this collection is marked with three numbers. None of the numbering sequences are complete. What should we do? 

In this situation creating yet another numbering system would probably be more confusing and marking the objects with another number could potentially spoil them. The best solution would be to choose one of the existing numbering systems to use in the accession register. This would depend on which is the most complete sequence, whether it was possible to work out which was the most original number and which had the best accompanying documentation. You would need to record why there are gaps in the numbering sequence and make sure that the other numbers were cross-referenced.

We know that our accession register has been re-written at least once in the past and that older versions were thrown away. The accession register we have now is not original and is unreliable.

This is not an argument for creating yet another version of the accession register. Firstly, if the numbering system works in linking the objects to information about them then it is not necessary to renumber. Secondly, you may know that your existing accession register is not the ‘original’ but it is the most original source of information that you have. Information may seem inaccurate but it was recorded for a reason and it is important to retain it. You can still annotate the accession register if necessary with your initials and the date or record queries in your catalogue record.

Date created: 2016

Publisher: Collections Trust