Choosing an object numbering system
An object number should remain useful when you move a collection, rename a category or discover that an attribution was wrong.
Give the number one job
Use the identifier to distinguish one record from every other record. Avoid packing a complete description into it. A code containing country, maker, year, condition and shelf location becomes fragile: new research or a move can make part of the code incorrect. A simple sequential number with a short collection prefix can remain stable while descriptive fields change.
Decide whether the identifier refers to a single object or a group. A model car with its original box and instructions may have one main record with separately described components. A tray of unrelated coins normally needs individual records if you expect to compare, move or sell them separately. The choice matters more than the punctuation used in the code.
Prevent collisions and accidental renumbering
Keep a master list of numbers already assigned and the next unused number. If two people add records, establish who allocates identifiers or give each person a separate temporary intake range. Do not reuse a number when an object leaves the collection. Retain a short record stating that it was transferred, otherwise an old photograph or receipt may later appear to refer to its replacement.
Leading zeros help filenames sort in a predictable order, but a spreadsheet may remove them unless the column is treated as text. Test your chosen format by saving, reopening and exporting a few records. Check that a number such as CVC-0007 stays unchanged and that a search finds the same object in both the spreadsheet and photograph folder.
Connect the label without marking the object
For a home collection, put the identifier on an appropriate enclosure, compartment or separate record card rather than improvising a permanent mark on the collectible. Make sure the label cannot be confused with the identity of a different object sharing the box. Never assume an adhesive label is suitable for direct contact with an old surface.
Photograph the object with a separate identifier card when making an inventory image, then take unobstructed photographs of important details. Keep the number in the image filename as well. This gives you more than one connection if an enclosure is replaced or a label becomes detached.
When splitting a group into individual records, preserve the old group identifier as a relationship field. Explain which new records came from it. That is preferable to silently changing every number, because purchase documents and earlier photographs may still refer to the original group.
