An object number may contain dots, letters or leading zeroes. In a spreadsheet, it can look like a date or an awkward decimal. Resist tidying it as though it were a measurement: its job is to identify a record.
Preserve the string you found
Copy the identifier with its punctuation and letter case, and keep the museum name beside it. Different collections can use similar-looking numbers. An identifier without its institution may be less useful than it first appears.
If a spreadsheet changes the value automatically, return to the source and store it as text using the application’s supported method. Do not reconstruct a lost prefix or zero from memory.
Separate identification from interpretation
Some numbering systems include an acquisition year or a group sequence, but their structure is institution-specific. A familiar-looking first section is not enough to establish a date. Record a date from the field that actually describes it, with its stated meaning.
For a fictional example, “A.0042.b” should remain that string. Converting it to “42” loses information even though a person may still feel they recognise the object.
Test whether the note leads back
Save the public record URL and collection name alongside the identifier. Later, try finding the same record from your note. If several results appear, compare titles and object details instead of selecting the first thumbnail.
Use a useful museum-record checklist as a companion. A good catalogue note makes retrieval possible; it does not need to decipher the museum’s entire internal system. Leaving the identifier intact is one of the simplest ways to preserve that route.